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Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
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1

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network [OSTI]

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

2

The investigation of high intensity laser driven micro neutron sources  

E-Print Network [OSTI]

, access to high temperature states of mat- ter capable of thermonuclear fusion and/or the effi- cientThe investigation of high intensity laser driven micro neutron sources for fusion materials. The application of fast pulse, high intensity lasers to drive low cost DT point neutron sources for fusion

Ghoniem, Nasr M.

3

Design of a free-electron laser driven by the LBNL laser-plasma-accelerator  

E-Print Network [OSTI]

plasma accelerator at the LBNL LOASIS facility”, in: Proc.electron laser driven by the LBNL laser-plasma-accelerator ?National Laboratory (LBNL) laser-plasma accelerator, whose

2008-01-01T23:59:59.000Z

4

Laser-driven relativistic electron beam interaction with solid dielectric  

SciTech Connect (OSTI)

The multi-frames shadowgraphy, interferometry and polarimetry diagnostics with sub-ps time resolution were used for an investigation of ionization wave dynamics inside a glass target induced by laser-driven relativistic electron beam. Experiments were done using the 50 TW Leopard laser at the UNR. For a laser flux of {approx}2 Multiplication-Sign 10{sup 18}W/cm{sup 2} a hemispherical ionization wave propagates at c/3. The maximum of the electron density inside the glass target is {approx}2 Multiplication-Sign 10{sup 19}cm{sup -3}. Magnetic and electric fields are less than {approx}15 kG and {approx}1 MV/cm, respectively. The electron temperature has a maximum of {approx}0.5 eV. 2D interference phase shift shows the 'fountain effect' of electron beam. The very low ionization inside glass target {approx}0.1% suggests a fast recombination at the sub-ps time scale. 2D PIC-simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields.

Sarkisov, G. S.; Ivanov, V. V.; Leblanc, P.; Sentoku, Y.; Yates, K.; Wiewior, P.; Chalyy, O.; Astanovitskiy, A.; Bychenkov, V. Yu.; Jobe, D.; Spielman, R. B. [Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (United States); Department of Physics, University of Nevada Reno, 5625 Fox Ave, Reno, NV, 89506 (United States); P.N. Lebedev Physics Institute, RAS, 53 Leninski Prospect, Moscow, 119991 (Russian Federation); Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (Russian Federation)

2012-07-30T23:59:59.000Z

5

Characterisation of electron beams from laser-driven particle accelerators  

SciTech Connect (OSTI)

The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2012-12-21T23:59:59.000Z

6

All-laser-driven, MeV-energy X-ray source for detection of SNM Sudeep Banerjee, Nathan Powers, Vidya Ramanathan, Nathaniel Cunningham, Nate Chandler-Smith, Shouyuan  

E-Print Network [OSTI]

All-laser-driven, MeV-energy X-ray source for detection of SNM Sudeep Banerjee, Nathan Powers, MI 48109. A quasi-monoenergetic MeV x-ray source based on laser-driven electron acceleration per laser shot. Characterization of such a high-flux high energy x-ray beam is in progress. Quasi

Umstadter, Donald

7

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P. Leemans  

E-Print Network [OSTI]

Physics of laser-driven plasma-based electron accelerators E. Esarey, C. B. Schroeder, and W. P Laser-driven plasma-based accelerators, which are capable of supporting fields in excess of 100 GV/m, are reviewed. This includes the laser wakefield accelerator, the plasma beat wave accelerator, the self

Geddes, Cameron Guy Robinson

8

Quantitative X-Ray Phase-Contrast Microtomography from a Compact Laser Driven Betatron Source  

E-Print Network [OSTI]

X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology. A laser-driven plasma wave accelerates and wiggles electrons, giving rise to brilliant keV X-ray emission. This so-called Betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability. Here we present the first phase-contrast micro-tomogram revealing quantitative electron density values of a biological sample using betatron X-rays, and a comprehensive source characterization. Our results suggest that laser-based X-ray technology offers the potential fo...

Wenz, J; Khrennikov, K; Bech, M; Thibault, P; Heigoldt, M; Pfeiffer, F; Karsch, S

2014-01-01T23:59:59.000Z

9

Characterization of a novel, short pulse laser-driven neutron source  

SciTech Connect (OSTI)

We present a full characterization of a short pulse laser-driven neutron source. Neutrons are produced by nuclear reactions of laser-driven ions deposited in a secondary target. The emission of neutrons is a superposition of an isotropic component into 4? and a forward directed, jet-like contribution, with energies ranging up to 80 MeV. A maximum flux of 4.4 × 10{sup 9} neutrons/sr has been observed and used for fast neutron radiography. On-shot characterization of the ion driver and neutron beam has been done with a variety of different diagnostics, including particle detectors, nuclear reaction, and time-of-flight methods. The results are of great value for future optimization of this novel technique and implementation in advanced applications.

Jung, D.; Falk, K.; Guler, N.; Devlin, M.; Favalli, A.; Fernandez, J. C.; Gautier, D. C.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Merrill, F.; Schoenberg, K.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wender, S. A.; Wilde, C. H.; Wurden, G. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Deppert, O. [Technische Universität Darmstadt, 64289 Darmstadt (Germany)] [Technische Universität Darmstadt, 64289 Darmstadt (Germany); and others

2013-05-15T23:59:59.000Z

10

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

SciTech Connect (OSTI)

Conceptual design of a bright electron injector for the 1 GeV high gradient test experiment. envisaged by the LLNL-SLAC-LBL collaboration on the Relativistic Klystron is presented. The design utilizes a high-brightness laser-driven RF photocathode electron gun, similar to the pioneering LANL early studies in concept (different parametrically however), together with achromatic magnetic bunching and transport systems and diagnostics. The design is performed with attention to possible use in an FEL as well. A simple but realistic analytic model including longitudinal and transverse space-charge and RF effects and extensive computer simulation form the basis of the parametric choice for the source. These parameters are used as guides for the design of the pico-second laser system and magnetic bunching section.

Chattopadhyay, S.; Chen, Y.J.; Hopkins, D.; Kim, K.J.; Kung, A.; Miller, R.; Sessler, a.; Young, T.

1988-09-01T23:59:59.000Z

11

Fountain effect of laser-driven relativistic electrons inside a solid dielectric  

SciTech Connect (OSTI)

Ultrafast interferometry with sub-ps resolution has been applied for the direct measurement of an electron density induced by a laser-driven relativistic electron beam inside a solid dielectric. The topology of the interference phase shift shows the signature of the ''fountain effect,'' a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields. The very low ionization, {approx}0.1%, observed after the heating pulse suggests a fast recombination at the sub-ps time scale.

Sarkisov, G. S.; Jobe, D.; Spielman, R. [Raytheon Ktech, 1300 Eubank Blvd., Albuquerque, New Mexico 87123 (United States); Leblanc, P.; Ivanov, V. V.; Sentoku, Y.; Yates, K.; Wiewior, P. [Department of Physics, University of Nevada, Reno, Nevada 89506 (United States); Bychenkov, V. Yu. [P.N. Lebedev Physical Institute, Leninski Pr. 53, Moscow 119991 (Russian Federation)

2011-09-26T23:59:59.000Z

12

Free-electron laser driven by the LBNL laser-plasma accelerator  

E-Print Network [OSTI]

XPLOTGIN, Technical Report LBNL-49625, Lawrence BerkeleyLASER-PLASMA ACCELERATOR AT THE LBNL LOASIS FACILITY,” inelectron laser driven by the LBNL laser-plasma accelerator

Schroeder, C. B.

2010-01-01T23:59:59.000Z

13

A Hybrid Laser-driven E-beam Injector Using Photo-cathode Electron Gun and superconducting Cavity*  

E-Print Network [OSTI]

A Hybrid Laser-driven E-beam Injector Using Photo-cathode Electron Gun and superconducting Cavity as a continuing effort towards a high-brightness superconducting RF injector. Various species of photo and one (betasuperconducting cavities operating under 2 K is to be constructed

Geng, Rong-Li

14

Effect of resistivity gradient on laser-driven electron transport and ion acceleration  

SciTech Connect (OSTI)

The effect of resistivity gradient on laser-driven electron transport and ion acceleration is investigated using collisional particle-in-cell simulation. The study is motivated by recent proton acceleration experiments [Gizzi et al., Phys. Rev. ST Accel. Beams 14, 011301 (2011)], which showed significant effect of the resistivity gradient in layered targets on the proton angular spread. This effect is reproduced in the present simulations. It is found that resistivity-gradient generation of magnetic fields and inhibition of electron transport is significantly enhanced when the feedback interaction between the magnetic field and the fast-electron current is included. Filamentation of the laser-generated hot electron jets inside the target, considered as the origin of the nonuniform proton patterns observed in the experiments, is clearly suppressed by the resistive magnetic field. As a result, the electrostatic sheath field at the target back surface acquires a relatively smooth profile, which contributes to the superior quality of the proton beams accelerated off layered targets in the experiments.

Zhuo, H. B.; Yang, X. H.; Ma, Y. Y.; Li, X. H. [College of Science, National University of Defense Technology, Changsha 410073 (China)] [College of Science, National University of Defense Technology, Changsha 410073 (China); Zhou, C. T. [College of Science, National University of Defense Technology, Changsha 410073 (China) [College of Science, National University of Defense Technology, Changsha 410073 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany)

2013-09-15T23:59:59.000Z

15

Proposed dielectric-based microstructure laser-driven undulator T. Plettner and R. L. Byer  

E-Print Network [OSTI]

by the possibility of future dielectric-based laser-driven particle accelerators that are expected to produce GeV=m accel- eration gradients accompanied by a low-emittance, low- energy spread, and high-repetition rate electron sources [8,9] as well as for dielectric-structure laser-driven particle accelerators are underway

Byer, Robert L.

16

Proof-Of-Principle Experiment for Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum  

SciTech Connect (OSTI)

We recently achieved the first experimental observation of laser-driven particle acceleration of relativistic electrons from a single Gaussian near-infrared laser beam in a semi-infinite vacuum. This article presents an in-depth account of key aspects of the experiment. An analysis of the transverse and longitudinal forces acting on the electron beam is included. A comparison of the observed data to the acceleration viewed as an inverse transition radiation process is presented. This is followed by a detailed description of the components of the experiment and a discussion of future measurements.

Plettner, T.; Byer, R.L.; /Stanford U., Phys. Dept.; Colby, E.; Cowan, B.; Sears, C.M.S.; Spencer, J.E.; Siemann, R.H.; /SLAC

2006-03-01T23:59:59.000Z

17

Photonic laser-driven accelerator for GALAXIE  

SciTech Connect (OSTI)

We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.

Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)

2012-12-21T23:59:59.000Z

18

Effects of initially energetic electrons on relativistic laser-driven electron plasma waves  

SciTech Connect (OSTI)

In this paper, using kinetic calculations and accurate 1D2V particle-in-cell simulations, we point out the important role of initially energetic electrons of the distribution tail in the behavior of high amplitude electron plasma waves (EPWs). In the presence of these electrons, the conventional warm fluid theory (WFT) breaks at very high wave amplitudes that are still noticeably lower than the wave breaking amplitude (WBA). The fluid breakdown results in electron super-heating with respect to the adiabatic laws. Indeed, a new kinetic regime of the relativistic EPWs appears below the WBA. It is argued that the mentioned super-heating results in WBA values lower than the corresponding WFT prediction.

Yazdanpanah, J., E-mail: jamal.yazdan@gmail.com; Anvari, A. [Department of Physics, Sharif University of Technology, P.O. Box 1155-4161, Tehran (Iran, Islamic Republic of)] [Department of Physics, Sharif University of Technology, P.O. Box 1155-4161, Tehran (Iran, Islamic Republic of)

2014-02-15T23:59:59.000Z

19

Design of a free-electron laser driven by the LBNLlaser-plasma-accelerator  

SciTech Connect (OSTI)

We discuss the design and current status of a compactfree-electron laser (FEL), generating ultra-fast, high-peak flux, VUVpulses driven by a high-current, GeV electron beam from the existingLawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator,whose active acceleration length is only a few cm. The proposedultra-fast source would be intrinsically temporally synchronized to thedrive laser pulse, enabling pump-probe studies in ultra-fast science withpulse lengths of tens of fs. Owing to the high current (&10 kA) ofthe laser-plasma-accelerated electron beams, saturated output fluxes arepotentially greater than 1013 photons/pulse. Devices based both on SASEand high-harmonic generated input seeds, to reduce undulator length andfluctuations, are considered.

Schroeder, C.B.; Fawley, W.M.; Montgomery, A.L.; Robinson, K.E.; Gruner, F.; Bakeman, M.; Leemans, W.P.

2007-09-10T23:59:59.000Z

20

Free-electron laser driven by the LBNL laser-plasma accelerator  

SciTech Connect (OSTI)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

Schroeder, C. B.; Fawley, W. M.; Gruner, F.; Bakeman, M.; Nakamura, K.; Robinson, K. E.; Toth, Cs.; Esarey, E.; Leemans, W. P.

2008-08-04T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Compact disposal of high-energy electron beams using passive or laser-driven plasma decelerating stage  

SciTech Connect (OSTI)

A plasma decelerating stage is investigated as a compact alternative for the disposal of high-energy beams (beam dumps). This could benefit the design of laser-driven plasma accelerator (LPA) applications that require transportability and or high-repetition-rate operation regimes. Passive and laser-driven (active) plasma-based beam dumps are studied analytically and with particle-in-cell (PIC) simulations in a 1D geometry. Analytical estimates for the beam energy loss are compared to and extended by the PIC simulations, showing that with the proposed schemes a beam can be efficiently decelerated in a centimeter-scale distance.

Bonatto, A.; Schroeder, C.B.; Vay, J.-L.; Geddes, C.R.; Benedetti, C.; Esarey and, E.; Leemans, W.P.

2014-07-13T23:59:59.000Z

22

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

E-Print Network [OSTI]

Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

23

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers  

SciTech Connect (OSTI)

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C{sup 6+}, O{sup 8+}, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Alejo, A.; Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Doria, D.; Green, A.; Jung, D.; Lewis, C. L. S.; Nersisyan, G. [Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Krygier, A. G.; Freeman, R. R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Clarke, R.; Green, J. S.; Notley, M. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fernandez, J. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Instituto de Fusión Nuclear, Universidad Politécnica de Madrid, 28006 Madrid (Spain); Fuchs, J. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Kleinschmidt, A.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt (Germany); Morrison, J. T. [Propulsion Systems Directorate, Air Force Research Lab, Wright Patterson Air Force Base, Ohio 45433 (United States); Najmudin, Z.; Nakamura, H. [Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); and others

2014-09-15T23:59:59.000Z

24

Generation of high-quality mega-electron volt proton beams with intense-laser-driven nanotube accelerator  

SciTech Connect (OSTI)

An ion acceleration scheme using carbon nanotubes (CNTs) is proposed, in which embedded fragments of low-Z materials are irradiated by an ultrashort intense laser to eject substantial numbers of electrons. Due to the resultant characteristic electrostatic field, the nanotube and embedded materials play the roles of the barrel and bullets of a gun, respectively, to produce highly collimated and quasimonoenergetic ion beams. Three-dimensional particle simulations, that take all the two-body Coulomb interactions into account, demonstrate generation of quasimonoenergetic MeV-order proton beams using nanometer-size CNT under a super-intense electrostatic field {approx}10{sup 14} V m{sup -1}.

Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)] [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Tanaka, M. [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)] [Department of Engineering, Chubu University, Aichi 487-8501 (Japan)

2013-04-22T23:59:59.000Z

25

Three-Dimensional Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

We discuss simulated photonic crystal structure designs for laser-driven particle acceleration, focusing on three-dimensional planar structures based on the so-called ''woodpile'' lattice. We describe guiding of a speed-of-light accelerating mode by a defect in the photonic crystal lattice and discuss the properties of this mode, including particle beam dynamics and potential coupling methods for the structure. We also discuss possible materials and power sources for this structure and their effects on performance parameters, as well as possible manufacturing techniques and the required tolerances. In addition we describe the computational technique and possible improvements in numerical modeling that would aid development of photonic crystal structures.

Cowan, B.; /SLAC

2006-09-07T23:59:59.000Z

26

Field emission electron source  

DOE Patents [OSTI]

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

2000-01-01T23:59:59.000Z

27

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered particle injection*  

E-Print Network [OSTI]

Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered; accepted 18 February 1998 Plasma-based accelerators are discussed in which high-power short pulse lasers are the power source, suitably tailored plasma structures provide guiding of the laser beam and support large

Wurtele, Jonathan

28

Direct Visualization of Laser-Driven Focusing Shock Waves  

E-Print Network [OSTI]

Direct real-time visualization and measurement of laser-driven shock generation, propagation, and 2D focusing in a sample are demonstrated. A substantial increase of the pressure at the convergence of the cylindrical ...

Pezeril, Thomas

29

Electron beam-based sources of ultrashort x-ray pulses.  

SciTech Connect (OSTI)

A review of various methods for generation of ultrashort x-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons is considered. The importance of the time-resolved studies of matter at picosecond (ps), femtosecond (fs), and atttosecond (as) time scales using x-rays has been widely recognized including by award of a Nobel Prize in 1999 [Zewa]. Extensive reviews of scientific drivers can be found in [BES1, BES2, BES3, Lawr, Whit]. Several laser-based techniques have been used to generate ultrashort x-ray pulses including laser-driven plasmas [Murn, Alte, Risc, Rose, Zamp], high-order harmonic generation [Schn, Rund, Wang, Arpi], and laser-driven anode sources [Ande]. In addition, ultrafast streak-camera detectors have been applied at synchrotron sources to achieve temporal resolution on the picosecond time scale [Wulf, Lind1]. In this paper, we focus on a different group of techniques that are based on the use of the relativistic electron beam produced in conventional accelerators. In the first part we review several techniques that utilize spontaneous emission of electrons and show how solitary sub-ps x-ray pulses can be obtained at existing storage ring based synchrotron light sources and linacs. In the second part we consider coherent emission of electrons in the free-electron lasers (FELs) and review several techniques for a generation of solitary sub-fs x-ray pulses. Remarkably, the x-ray pulses that can be obtained with the FELs are not only significantly shorter than the ones considered in Part 1, but also carry more photons per pulse by many orders of magnitude.

Zholents, A.; Accelerator Systems Division (APS)

2010-09-30T23:59:59.000Z

30

Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

Cowan, Benjamin M.

2007-08-22T23:59:59.000Z

31

The Argonne laser-driven D target: Recent developments and progress  

SciTech Connect (OSTI)

The first direct measurements of nuclear tensor polarization p{sub zz} in a laser-driven polarized D target have been performed at Argonne. We present p{sub zz} and electron polarization P{sub e} data taken at a magnetic field of 600 G in the optical pumping cell. These results are highly indicative that spin-temperature equilibrium is achieved in the system. To prevent spin relaxation of D and K atoms as well as the molecular recombination of D atoms, the walls of the laser-driven D target are coated with organosilane compounds. We discuss a new coating technique, the {open_quotes}afterwash{close_quotes}, developed at Argonne which has yielded stable atomic fraction results when the coating is exposed to K. We also present new coating techniques for glass and Cu substrates.

Fedchak, J.A.; Bailey, K.; Cummings, W.J. [and others

1997-11-01T23:59:59.000Z

32

Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light  

E-Print Network [OSTI]

Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light dura- tions (femtosecond). Pulses of -rays, electrons, and laser light are also well synchronized); published July 7, 2014 Gamma-ray photons with energy >9 MeV were produced when second

Umstadter, Donald

33

Attosecond Thomson-scattering x-ray source driven by laser-based electron acceleration  

SciTech Connect (OSTI)

The possibility of producing attosecond x-rays through Thomson scattering of laser light off laser-driven relativistic electron beams is investigated. For a ?200-as, tens-MeV electron bunch produced with laser ponderomotive-force acceleration in a plasma wire, exceeding 10{sup 6} photons/s in the form of ?160 as pulses in the range of 3–300 keV are predicted, with a peak brightness of ?5 × 10{sup 20} photons/(s mm{sup 2} mrad{sup 2} 0.1% bandwidth). Our study suggests that the physical scheme discussed in this work can be used for an ultrafast (attosecond) x-ray source, which is the most beneficial for time-resolved atomic physics, dubbed “attosecond physics.”.

Luo, W. [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China) [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); College of Science, National University of Defense Technology, Changsha 410073 (China); Zhuo, H. B.; Yu, T. P. [College of Science, National University of Defense Technology, Changsha 410073 (China)] [College of Science, National University of Defense Technology, Changsha 410073 (China); Ma, Y. Y. [College of Science, National University of Defense Technology, Changsha 410073 (China) [College of Science, National University of Defense Technology, Changsha 410073 (China); Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Song, Y. M.; Zhu, Z. C. [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China)] [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Yu, M. Y. [Department of Physics, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Department of Physics, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Theoretical Physics I, Ruhr University, D-44801 Bochum (Germany)

2013-10-21T23:59:59.000Z

34

Proposed Laser-driven, Dielectric Microstructure Few-cm Long Undulator for Attosecond Coherent X-rays  

SciTech Connect (OSTI)

This article presents the concept of an all-dielectric laser-driven undulator for the generation of coherent X-rays. The proposed laser-driven undulator is expected to produce internal deflection forces equivalent to a several-Tesla magnetic field acting on a speed-of-light particle. The key idea for this laser-driven undulator is its ability to provide phase synchronicity between the deflection force and the electron beam for a distance that is much greater than the laser wavelength. The potential advantage of this undulator is illustrated with a possible design example that assumes a small laser accelerator which delivers a 2 GeV, 1 pC, 1 kHz electron bunch train to a 10 cm long, 1/2 mm period laser-driven undulator. Such an undulator could produce coherent X-ray pulses with {approx}10{sup 9} photons of 64 keV energy. The numerical modeling for the expected X-ray pulse shape was performed with GENESIS, which predicts X-ray pulse durations in the few-attosecond range. Possible applications for nonlinear electromagnetic effects from these X-ray pulses are briefly discussed.

Plettner, T; Byer, R.L.; /Stanford U., Ginzton Lab.

2011-09-16T23:59:59.000Z

35

E-Print Network 3.0 - atom laser driven Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

laser driven Search Powered by Explorit Topic List Advanced Search Sample search results for: atom laser driven Page: << < 1 2 3 4 5 > >> 1 (For McGraw-Hill 1999 Yearbook of...

36

Biomedical Imaging with Partially Coherent Laser Driven Plasma Xray Sources  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCouldBiofuelHelpBiologyB I I O O mBiomedical

37

ECR ion source with electron gun  

DOE Patents [OSTI]

An Advanced Electron Cyclotron Resonance ion source having an electron gun for introducing electrons into the plasma chamber of the ion source is described. The ion source has a injection enclosure and a plasma chamber tank. The plasma chamber is defined by a plurality of longitudinal magnets. The electron gun injects electrons axially into the plasma chamber such that ionization within the plasma chamber occurs in the presence of the additional electrons produced by the electron gun. The electron gun has a cathode for emitting electrons therefrom which is heated by current supplied from an AC power supply while bias potential is provided by a bias power supply. A concentric inner conductor and outer conductor carry heating current to a carbon chuck and carbon pusher which hold the cathode in place and also heat the cathode. In the Advanced Electron Cyclotron Resonance ion source, the electron gun replaces the conventional first stage used in prior electron cyclotron resonance ion generators. 5 figures.

Xie, Z.Q.; Lyneis, C.M.

1993-10-26T23:59:59.000Z

38

Laser-driven shock experiments in pre-compressed water: Implications for magnetic field generation in Icy Giant planets  

SciTech Connect (OSTI)

Laser-driven shock compression of pre-compressed water (up to 1 GPa precompression) produces high-pressure, -temperature conditions in the water inducing two optical phenomena: opacity and reflectivity in the initially transparent water. The onset of reflectivity at infrared wavelengths can be interpreted as a semi-conductor to electronic conductor transition in water and is found at pressures above {approx}130 GPa for single-shocked samples pre-compressed to 1 GPa. This electronic conduction provides an additional contribution to the conductivity required for magnetic field generation in Icy Giant planets like Uranus and Neptune.

Lee, K; Benedetti, L R; Jeanloz, R; Celliers, P M; Eggert, J H; Hicks, D G; Moon, S J; Mackinnon, A; Henry, E; Koenig, M; Benuzzi-Mounaix, A; Collins, G W

2005-11-10T23:59:59.000Z

39

Acceleration-field calculation for a structure-based laser-driven linear accelerator  

E-Print Network [OSTI]

Acceleration-field calculation for a structure-based laser-driven linear accelerator Y. C. Huanga for publication 16 April 1998 A laser-driven particle accelerator, scaled to optical wavelengths, has a feature size many orders of magnitude smaller than a radio-frequency accelerator. However, similar to a radio

Byer, Robert L.

40

Studies of laser-driven radiative blast waves  

SciTech Connect (OSTI)

We have performed two sets of experiments looking at laser-driven radiating blast waves. In one set of experiments the effect of a drive laser's passage through a background gas on the hydrodynamical evolution of blast waves was examined. It was found that the laser's passage heats a channel in the gas, creating a region where a portion of the blast wave front had an increased velocity, leading to the formation of a bump-like protrusion on the blast wave. The second set of experiments involved the use of regularly spaced wire arrays to induce perturbations on a blast wave surface. The decay of these perturbations as a function of time was measured for various wave number perturbations and found to be in good agreement with theoretical predictions.

Edwards, M J; Hansen, J; Edens, A; Ditmire, T; Adams, R; Rambo, P; Ruggles, L; Smith, I; Porter, J

2004-04-29T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

Brainard, J.P.; McCollister, D.R.

1998-04-28T23:59:59.000Z

42

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

Brainard, John P. (Albuquerque, NM); McCollister, Daryl R. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

43

Plasma-Density Determination from X-Ray Radiography of Laser-Driven Spherical Implosions  

E-Print Network [OSTI]

The fuel layer density of an imploding laser-driven spherical shell is inferred from framed x-ray radiographs. The density distribution is determined by using Abel inversion to compute the radial distribution of the opacity ...

Frenje, Johan A.

44

The Electron Beam Ion Source (EBIS)  

ScienceCinema (OSTI)

Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

Brookhaven Lab

2010-01-08T23:59:59.000Z

45

Stimulated scattering in laser driven fusion and high energy density physics experiments  

SciTech Connect (OSTI)

In laser driven fusion and high energy density physics experiments, one often encounters a k?{sub D} range of 0.15?electron plasma wave number and ?{sub D} is the Debye length). Using particle-in-cell simulations, the SRS reflectivity is found to scale as ? (k?{sub D}){sup ?4} for k?{sub D} ? 0.3 where electron trapping effects dominate SRS saturation; the reflectivity scaling deviates from the above for k?{sub D}?electron temperature variation from collisional heating, the latter of which reduces gain, introduces a positive frequency shift that counters the trapping-induced negative frequency shift, and affects SRS and SBS saturation. Bowing and breakup of ion-acoustic wavefronts saturate SBS and cause a dramatic, sharp decrease in SBS reflectivity. Mitigation of SRS and SBS in the strongly nonlinear trapping regime is discussed.

Yin, L., E-mail: lyin@lanl.gov; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Finnegan, S. M.; Bergen, B.; Bowers, K. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kirkwood, R. K.; Milovich, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2014-09-15T23:59:59.000Z

46

Positron source position sensing detector and electronics  

DOE Patents [OSTI]

A positron source, position sensing device, particularly with medical applications, in which positron induced gamma radiation is detected using a ring of stacked, individual scintillation crystals, a plurality of photodetectors, separated from the scintillation crystals by a light guide, and high resolution position interpolation electronics. Preferably the scintillation crystals are several times more numerous than the photodetectors with each crystal being responsible for a single scintillation event from a received gamma ray. The light guide will disperse the light emitted from gamma ray absorption over several photodetectors. Processing electronics for the output of the photodetectors resolves the location of the scintillation event to a fraction of the dimension of each photodetector. Because each positron absorption results in two 180.degree. oppositely traveling gamma rays, the detection of scintillation in pairs permits location of the positron source in a manner useful for diagnostic purposes. The processing electronics simultaneously responds to the outputs of the photodetectors to locate the scintillations to the source crystal. While it is preferable that the scintillation crystal include a plurality of stacked crystal elements, the resolving power of the processing electronics is also applicable to continuous crystal scintillators.

Burnham, Charles A. (South Essex, MA); Bradshaw, Jr., John F. (Winthrop, MA); Kaufman, David E. (Brockton, MA); Chesler, David A. (Newton Highlands, MA); Brownell, Gordon L. (Cambridge, MA)

1985-01-01T23:59:59.000Z

47

Update on the Electron Source Model  

SciTech Connect (OSTI)

We summarize work done in FY12 on the Los Alamos Electron Source Model (ESM), which predicts the distribution of beta-decay electrons after a high altitude nuclear explosion (HANE) as a function of L, energy, and pitch angle. In the last year we have compared model results with data taken after the Russian 2 HANE test of 1962 and presented results at the HEART conference. We discuss our future plans to continue comparison with HANE data and to develop the code to allow a more complex set of initial conditions.

Cowee, Misa [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory

2012-07-17T23:59:59.000Z

48

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER*  

E-Print Network [OSTI]

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER* J.S. Wurtele and AV on 1 TeV) are applied to free-space laser and laser/plasma accelerators. It is shown that the requirements impose very severe constraints upon the new accelerators-- so severe, that it seems unlikely

Wurtele, Jonathan

49

STUDIES OF LASER-DRIVEN RADIATIVE BLAST WAVES A.D. EDENS1  

E-Print Network [OSTI]

-driven radiating blast waves. In the first set of experiments the effect of a drive laser's passage throughSTUDIES OF LASER-DRIVEN RADIATIVE BLAST WAVES A.D. EDENS1 , T. DITMIRE1 , J.F. HANSEN2 , M a background gas on the hydrodynamical evolution of blast waves was examined. The laser's passage heated

Ditmire, Todd

50

Laser-Driven Accelerated Growth of Dendritic Patterns in Liquids Himanish Basu,  

E-Print Network [OSTI]

Laser-Driven Accelerated Growth of Dendritic Patterns in Liquids Himanish Basu, Kiran M. Kolwankar: We report a scheme for very significantly accelerated growth of dendritic patterns in organic the time evolution of the accelerated growth patterns; growth patterns are seen on millisecond time scales

Sharma, Shobhona

51

DENSE MATTER IN LASER DRIVEN FUSION ! LABORATORY EXPERIMENTS R.L. Mc Crory and J. Wilson  

E-Print Network [OSTI]

irradiation to heat and compress a target containing thermonuclear fuel to fusion conditions. This is stillDENSE MATTER IN LASER DRIVEN FUSION ! LABORATORY EXPERIMENTS R.L. Mc Crory and J. Wilson Laboratory. The high power lasers in quaestion were constructed with laser fusion studies as the goal, i

Boyer, Edmond

52

Femtosecond laser-electron x-ray source  

DOE Patents [OSTI]

A femtosecond laser-electron X-ray source. A high-brightness relativistic electron injector produces an electron beam pulse train. A system accelerates the electron beam pulse train. The femtosecond laser-electron X-ray source includes a high intra-cavity power, mode-locked laser and an x-ray optics system.

Hartemann, Frederic V.; Baldis, Hector A.; Barty, Chris P.; Gibson, David J.; Rupp, Bernhard

2004-04-20T23:59:59.000Z

53

Infrared light sources with semimetal electron injection  

DOE Patents [OSTI]

An infrared light source is disclosed that comprises a layered semiconductor active region having a semimetal region and at least one quantum-well layer. The semimetal region, formed at an interface between a GaAsSb or GalnSb layer and an InAsSb layer, provides electrons and holes to the quantum-well layer to generate infrared light at a predetermined wavelength in the range of 2-6 .mu.m. Embodiments of the invention can be formed as electrically-activated light-emitting diodes (LEDs) or lasers, and as optically-pumped lasers. Since the active region is unipolar, multiple active regions can be stacked to form a broadband or multiple-wavelength infrared light source.

Kurtz, Steven R. (Albuquerque, NM); Biefeld, Robert M. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

54

Laser-driven relativistic tunneling from p-states  

E-Print Network [OSTI]

The tunneling ionization of an electron from a p-state in a highly charged ion in the relativistic regime is investigated in a linearly polarized strong laser field. In contrast to the case of an s-state, the tunneling ionization from the p-state is spin asymmetric. We have singled out two reasons for the spin asymmetry: first, the difference of the electron energy Zeeman splitting in the bound state and during tunneling, and second, the relativistic momentum shift along the laser propagation direction during the under-the barrier motion. Due to the latter, those states are predominantly ionized where the electron rotation is opposite to the electron relativistic shift during the under-the-barrier motion. We have investigated the dependence of the ionization rate on the laser intensity for different projections of the total angular momentum and identified the intensity parameter which governs this behaviour. The significant change of the ionization rate is originated from the different precession dynamics of the total angular momentum in the bound state at high and low intensities.

Michael Klaiber; Karen Z. Hatsagortsyan

2014-10-20T23:59:59.000Z

55

Advances in laser driven accelerator R&D  

SciTech Connect (OSTI)

Current activities (last few years) at different laboratories, towards the development of a laser wakefield accelerator (LWFA) are reviewed, followed by a more in depth discussion of results obtained at the L'OASIS laboratory of LBNL. Recent results on laser guiding of relativistically intense beams in preformed plasma channels are discussed. The observation of mono-energetic beams in the 100 MeV energy range, produced by a channel guided LWFA at LBNL, is described and compared to results obtained in the unguided case at LOA, RAL and LBNL. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator has a very beneficial impact on the electron energy distribution. Progress on laser triggered injection is reviewed. Results are presented on measurements of bunch duration and emittance of the accelerated electron beams, that indicate the possibility of generating femtosecond duration electron bunches. Future challenges and plans towards the development of a 1 GeV LWFA module are discussed.

Leemans, Wim

2004-08-23T23:59:59.000Z

56

Electron Injector Studies at LBL  

E-Print Network [OSTI]

Photocathode RF Electron Gun", S. Chattopadhyay, Y. J. Chen,Emittances in Laser-driven Rf Guns", K. J. Kim and Y. J.Brightness RF Photocathode Guns for LLNL-SLAC-LBL 1 GeV Test

Kim, C.H.

2010-01-01T23:59:59.000Z

57

SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) to be constructed at ORNL is a collaboration of six laboratories. Beam current monitors for SNS will be used to monitor H-minus and H-plus beams ranging from the 15 mA (tune-up in the Front End and Linac) to over 60 A fully accumulated in the Ring. The time structure of the beams to be measured range from 645 nsec ''mini'' bunches, at the 1.05 MHz ring revolution rate, to an overall 1 mS long macro pulse. Beam current monitors (BCMs) for SNS have requirements depending upon their location within the system. The development of a general approach to satisfy requirements of various locations with common components is a major design objective. This paper will describe the development of the beam current monitors and electronics.

KESSELMAN, M.

2001-06-18T23:59:59.000Z

58

Laser Electron Gamma Source. Biennial progress report  

SciTech Connect (OSTI)

The LEGS facility provides intense, polarized, monochromatic {gamma}-ray beams by Compton backscattering laser light from relativistic electrons circulating in the X-Ray storage ring of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. With the start of ring operations at 2.8 GeV, LEGS {gamma}-ray energies now extend to 370 MeV. Considerable progress has been made in the development of a new laser system that will increase the beam energies to 470 MeV, and this system is expected to come into operation before the next biennial report. The total flux is administratively held at 6 {times} 10{sup 6} s{sup {minus}1}. The {gamma}-ray energy is determined, with a resolution of 5.5 MeV, by detecting the scattering electrons in a magnetic spectrometer. This spectrometer can `tag` all {gamma}-rays with energies from 185 MeV up to the Compton edge. The beam spot size at the target position is 8 mm (V) {times} 18 mm (H), FWHM. For a single laser wavelength, the linear polarization of the beam is 98% at the Compton edge and decreases to 50% at about 1/2 the energy of the edge. By choosing the laser wavelengths appropriately the polarization can be maintained above 85% throughout the tagging range. During the last two years, experimental running at LEGS occupied an average of 3000 hours annually. Highlights of some of the programs are discussed below.

Sandorfi, A.M. [ed.; Caracappa, A.; Kuczewski, A.; Kistner, O.C.; Lincoln, F.; Miceli, L.; Thorn, C.E. [Brookhaven National Lab., Upton, NY (United States); Hoblit, S. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Physics; Khandaker, M. [Brookhaven National Lab., Upton, NY (United States)]|[Virginia Polytechnic Institute & State Univ., Blacksburg, VA (United States). Dept. of Physics

1994-06-01T23:59:59.000Z

59

Investigation of Ultrafast Laser-Driven Radiative Blast Waves  

SciTech Connect (OSTI)

We have examined the evolution of cylindrically symmetric blast waves produced by the deposition of femtosecond laser pulses in gas jets. In high-Z gases radiative effects become important. We observe the production of an ionization precursor ahead of the shock front and deceleration parameters below the adiabatic value of 1/2 (for a cylinder), an effect expected when the blast wave loses energy by radiative cooling. Despite significant radiative cooling, the blast waves do not appear to develop thin shell instabilities expected for strongly radiative waves. This is believed to be due to the stabilizing effect of a relatively thick blast wave shell resulting in part from electron thermal conduction effects.

Edwards, M. J.; MacKinnon, A. J.; Zweiback, J.; Shigemori, K.; Ryutov, D.; Rubenchik, A. M.; Keilty, K. A.; Liang, E.; Remington, B. A.; Ditmire, T.

2001-08-20T23:59:59.000Z

60

High-current-density, high brightness cathodes for free electron laser applications  

SciTech Connect (OSTI)

This report discusses the following topics: brightness and emittance of electron beams and cathodes; general requirements for cathodes in high brightness electron guns; candidate cathode types; plasma and field emission cathodes; true field emission cathodes; oxide cathodes; lanthanum hexaborides cathodes; laser driven thermionic cathodes; laser driven photocathodes; impregnated porous tungsten dispenser cathodes; and choice of best performing cathode types.

Green, M.C. (Varian Associates, Palo Alto, CA (USA). Palo Alto Microwave Tube Div.)

1987-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Proposal for a High-Brightness Pulsed Electron Source  

SciTech Connect (OSTI)

We propose a novel scheme for a high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography. A description of the proposed scheme is presented.

Zolotorev, M.; Commins, E.D.; Heifets, S.; Sannibale, F.; /LBL, Berkeley /UC, Berkeley /SLAC

2006-10-16T23:59:59.000Z

62

High-intensity laser-driven proton acceleration enhancement from hydrogen containing ultrathin targets  

SciTech Connect (OSTI)

Laser driven proton acceleration experiments from micron and submicron thick targets using high intensity (2 × 10{sup 21} W/cm{sup 2}), high contrast (10{sup ?15}) laser pulses show an enhancement of maximum energy when hydrogen containing targets were used instead of non-hydrogen containing. In our experiments, using thin (<1?m) plastic foil targets resulted in maximum proton energies that were consistently 20%–100% higher than when equivalent thickness inorganic targets, including Si{sub 3}N{sub 4} and Al, were used. Proton energies up to 20 MeV were measured with a flux of 10{sup 7} protons/MeV/sr.

Dollar, F.; Reed, S. A.; Matsuoka, T.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; McGuffey, C.; Rousseau, P.; Thomas, A. G. R.; Willingale, L.; Yanovsky, V.; Krushelnick, K.; Maksimchuk, A. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Litzenberg, D. W. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2013-09-30T23:59:59.000Z

63

BROADBAND ANALOG OPTO-ELECTRONIC BLIND SOURCE SEPARATION  

E-Print Network [OSTI]

-electronic blind source separation Thesis directed by Professor Zoya Popovi´c This thesis addresses the problemBROADBAND ANALOG OPTO-ELECTRONIC BLIND SOURCE SEPARATION by PAUL CARSON SMITH B.E., University of Colorado, 2000 M.S., University of Colorado, 2000 A thesis submitted to the Faculty of the Graduate School

Popovic, Zoya

64

Electron cyclotron resonance microwave ion sources for thin film processing  

SciTech Connect (OSTI)

Plasmas created by microwave absorption at the electron cyclotron resonance (ECR) are increasingly used for a variety of plasma processes, including both etching and deposition. ECR sources efficiently couple energy to electrons and use magnetic confinement to maximize the probability of an electron creating an ion or free radical in pressure regimes where the mean free path for ionization is comparable to the ECR source dimensions. The general operating principles of ECR sources are discussed with special emphasis on their use for thin film etching. Data on source performance during Cl base etching of Si using an ECR system are presented. 32 refs., 5 figs.

Berry, L.A.; Gorbatkin, S.M.

1990-01-01T23:59:59.000Z

65

Model Reduction for Power Electronics Systems with Multiple Heat Sources  

E-Print Network [OSTI]

Model Reduction for Power Electronics Systems with Multiple Heat Sources A. Augustin, T. Hauck, B demonstrates the model order re- duction procedures applied to semiconductor devices with multiple heat sources. The approach is demonstrated for a device with nine heat sources where some of them are perma- nently active

Paris-Sud XI, Université de

66

Abstract--Grazing incidence metal mirrors in laser-driven IFE power plants are subject to a variety of threats that result  

E-Print Network [OSTI]

Abstract--Grazing incidence metal mirrors in laser-driven IFE power plants are subject to a variety [4] at UCSD, and help define design windows for the GIMM in a laser-driven IFE power plant of threats that result in damages leading to increased laser absorption, beam quality degradation and reduced

Tillack, Mark

67

ILC Polarized Electron Source Design and R&D Program  

SciTech Connect (OSTI)

The R and D program for the ILC electron focuses on three areas. These are the source drive laser system, the electron gun and photo cathodes necessary to produce a highly polarized electron beam. Currently, the laser system and photo cathode development take place at SLAC's 'ILC Injector Test facility', which is an integrated lab (laser and gun) that allows the production of the electron beam and is equipped with a set of diagnostics, necessary to characterize the source performance. Development of the ILC electron gun takes place at Jefferson Lab, where advanced concepts and technologies for HV DC electron guns for polarized beams are being developed. The goal is to combine both efforts at one facility to demonstrate an electron beam with ILC specifications, which are electron beam charge and polarization as well as the cathode's lifetime. The source parameters are summarized in Table 1. The current schematic design of the ILC central complex is depicted in Figure 1. The electron and positron sources are located and laid out approximately symmetric on either side of the damping rings.

Brachmann, A.; Sheppard, J.; Zhou, F.; Poelker, M.; /SLAC

2012-04-06T23:59:59.000Z

68

Proposal for a High-Brightness Pulsed Electron Source  

SciTech Connect (OSTI)

We propose a novel scheme for a high-brightness pulsedelectron source, which has the potential for many useful applications inelectron microscopy, inverse photo-emission, low energy electronscattering experiments, and electron holography. A description of theproposed scheme is presented.

Zolotorev, Max; Commins, Eugene D.; Heifets, Sam; Sannibale,Fernando

2006-03-15T23:59:59.000Z

69

Demonstartion of density dependence of x-ray flux in a laser-driven hohlraum  

SciTech Connect (OSTI)

Experiments have been conducted using laser-driven cylindrical hohlraums whose walls are machined from Ta{sub 2}O{sub 5} foams of 100 mg/cc and 4 g/cc densities. Measurements of the radiation temperature demonstrate that the lower density walls produce higher radiation temperatures than the high density walls. This is the first experimental demonstration of the prediction that this would occur [M. D. Rosen and J. H. Hammer, Phys. Rev. E 72, 056403 (2005)]. For high density walls, the radiation front propagates subsonically, and part of the absorbed energy is wasted by the flow kinetic energy. For the lower wall density, the front velocity is supersonic and can devote almost all of the absorbed energy to heating the wall.

Young, P E; Rosen, M D; Hammer, J H; Hsing, W S; Glendinning, S G; Turner, R E; Kirkwood, R; Schein, J; Sorce, C; Satcher, J; Hamza, A; Reibold, R A; Hibbard, R; Landen, O; Reighard, A; McAlpin, S; Stevenson, M; Thomas, B

2008-02-11T23:59:59.000Z

70

Investigation of laser-driven proton acceleration using ultra-short, ultra-intense laser pulses  

SciTech Connect (OSTI)

We report optimization of laser-driven proton acceleration, for a range of experimental parameters available from a single ultrafast Ti:sapphire laser system. We have characterized laser-generated protons produced at the rear and front target surfaces of thin solid targets (15 nm to 90 {mu}m thicknesses) irradiated with an ultra-intense laser pulse (up to 10{sup 20} W Dot-Operator cm{sup -2}, pulse duration 30 to 500 fs, and pulse energy 0.1 to 1.8 J). We find an almost symmetric behaviour for protons accelerated from rear and front sides, and a linear scaling of proton energy cut-off with increasing pulse energy. At constant laser intensity, we observe that the proton cut-off energy increases with increasing laser pulse duration, then roughly constant for pulses longer than 300 fs. Finally, we demonstrate that there is an optimum target thickness and pulse duration.

Fourmaux, S.; Gnedyuk, S.; Lassonde, P.; Payeur, S.; Pepin, H.; Kieffer, J. C. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Buffechoux, S.; Albertazzi, B. [INRS-EMT, Universite du Quebec, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Capelli, D.; Antici, P. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Dipartimento SBAI, Sapienza, Universita di Roma, Via Scarpa 16, 00161 Roma (Italy); Levy, A.; Fuchs, J. [LULI, UMR 7605, CNRS - CEA - Universite Paris 6 - Ecole Polytechnique, 91128 Palaiseau (France); Lecherbourg, L.; Marjoribanks, R. S. [Department of Physics and Institute for Optical Sciences, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

2013-01-15T23:59:59.000Z

71

Progress on a cryogenically cooled RF gun polarized electron source  

SciTech Connect (OSTI)

RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

Fliller, R.P., III; Edwards, H.; /Fermilab

2006-08-01T23:59:59.000Z

72

Project Execution Plan Electron Beam Ion Source Project  

E-Print Network [OSTI]

Project Execution Plan for the Electron Beam Ion Source Project (EBIS) Project # 07-SC-02 at Brookhaven National Laboratory Upton, NY For the U.S. Department of Energy Office of Science Office of Nuclear Physics (SC ­ 26) Rev. 1 May 2008 #12;#12;#12;4 Project Execution Plan for the Electron Beam Ion

73

A compact, versatile low-energy electron beam ion source  

SciTech Connect (OSTI)

A new compact Electron Beam Ion Source, the Dresden EBIT-LE, is introduced as an ion source working at low electron beam energies. The EBIT-LE operates at an electron energy ranging from 100 eV to some keV and can easily be modified to an EBIT also working at higher electron beam energies of up to 15 keV. We show that, depending on the electron beam energy, electron beam currents from a few mA in the low-energy regime up to about 40 mA in the high-energy regime are possible. Technical solutions as well as first experimental results of the EBIT-LE are presented. In ion extraction experiments, a stable production of low and intermediate charged ions at electron beam energies below 2 keV is demonstrated. Furthermore, X-ray spectroscopy measurements confirm the possibility of using the machine as a source of X-rays from ions excited at low electron energies.

Zschornack, G., E-mail: g.zschornack@hzdr.de [Department of Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden (Germany); König, J.; Schmidt, M.; Thorn, A. [DREEBIT GmbH, 01109 Dresden (Germany)] [DREEBIT GmbH, 01109 Dresden (Germany)

2014-02-15T23:59:59.000Z

74

Electron Beam Collimation for the Next Generation Light Source  

SciTech Connect (OSTI)

The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

2013-05-20T23:59:59.000Z

75

Blast Wave Formation by Laser-Sustained Nonequilibrium Plasma in the Laser-Driven In-Tube Accelerator Operation  

SciTech Connect (OSTI)

Understanding the dynamics of laser-produced plasma is essentially important for increasing available thrust force in a gas-driven laser propulsion system such as laser-driven in-tube accelerator. A computer code is developed to explore the formation of expanding nonequilibrium plasma produced by laser irradiation. Various properties of the blast wave driven by the nonequilibrium plasma are examined. It is found that the blast wave propagation is substantially affected by radiative cooling effect for lower density case.

Ogino, Yousuke; Ohnishi, Naofumi; Sawada, Keisuke [Department of Aeronautics and Space Engineering, Tohoku University, Sendai 980-8579 (Japan); Sasoh, Akihiro [Institute of Fluid Science, Tohoku University, Sendai 980-8577 (Japan)

2006-05-02T23:59:59.000Z

76

Laser-driven, magnetized quasi-perpendicular collisionless shocks on the Large Plasma Device  

SciTech Connect (OSTI)

The interaction of a laser-driven super-Alfvénic magnetic piston with a large, preformed magnetized ambient plasma has been studied by utilizing a unique experimental platform that couples the Raptor kJ-class laser system [Niemann et al., J. Instrum. 7, P03010 (2012)] to the Large Plasma Device [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] at the University of California, Los Angeles. This platform provides experimental conditions of relevance to space and astrophysical magnetic collisionless shocks and, in particular, allows a detailed study of the microphysics of shock formation, including piston-ambient ion collisionless coupling. An overview of the platform and its capabilities is given, and recent experimental results on the coupling of energy between piston and ambient ions and the formation of collisionless shocks are presented and compared to theoretical and computational work. In particular, a magnetosonic pulse consistent with a low-Mach number collisionless shock is observed in a quasi-perpendicular geometry in both experiments and simulations.

Schaeffer, D. B., E-mail: dschaeffer@physics.ucla.edu; Everson, E. T.; Bondarenko, A. S.; Clark, S. E.; Constantin, C. G.; Vincena, S.; Van Compernolle, B.; Tripathi, S. K. P.; Gekelman, W.; Niemann, C. [Department of Physics and Astronomy, University of California - Los Angeles, Los Angeles, California 90095 (United States); Winske, D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-05-15T23:59:59.000Z

77

Novel free-form hohlraum shape design and optimization for laser-driven inertial confinement fusion  

SciTech Connect (OSTI)

The hohlraum shape attracts considerable attention because there is no successful ignition method for laser-driven inertial confinement fusion at the National Ignition Facility. The available hohlraums are typically designed with simple conic curves, including ellipses, parabolas, arcs, or Lame curves, which allow only a few design parameters for the shape optimization, making it difficult to improve the performance, e.g., the energy coupling efficiency or radiation drive symmetry. A novel free-form hohlraum design and optimization approach based on the non-uniform rational basis spline (NURBS) model is proposed. In the present study, (1) all kinds of hohlraum shapes can be uniformly represented using NURBS, which is greatly beneficial for obtaining the optimal available hohlraum shapes, and (2) such free-form uniform representation enables us to obtain an optimal shape over a large design domain for the hohlraum with a more uniform radiation and higher drive temperature of the fuel capsule. Finally, a hohlraum is optimized and evaluated with respect to the drive temperature and symmetry at the Shenguang III laser facility in China. The drive temperature and symmetry results indicate that such a free-form representation is advantageous over available hohlraum shapes because it can substantially expand the shape design domain so as to obtain an optimal hohlraum with high performance.

Jiang, Shaoen; Jing, Longfei, E-mail: scmyking-2008@163.com; Ding, Yongkun [Laser Fusion Research Center, China Academy Engineering Physics, Mianyang 621900 (China); Huang, Yunbao, E-mail: huangyblhy@gmail.com [Mechatronics School of Guangdong University of Technology, Guangzhou 510006 (China)

2014-10-15T23:59:59.000Z

78

Laser-driven platform for generation and characterization of strong quasi-static magnetic fields  

E-Print Network [OSTI]

Quasi-static magnetic-fields up to $800\\,$T are generated in the interaction of intense laser pulses (500J, 1ns, 10^{17}W/cm^2) with capacitor-coil targets of different materials. The reproducible magnetic-field was consistently measured by three independent diagnostics: GHz-bandwidth inductor pickup coils (B-dot probes), Faraday rotation of polarized optical laser light and proton beam-deflectometry. The field rise time is consistent with the laser pulse duration, and it has a dipole-like distribution over a characteristic volume of 1mm^3, which is coherent with theoretical expectations. These results demonstrate a very efficient conversion of the laser energy into magnetic fields, thus establishing a robust laser-driven platform for reproducible, well characterized, generation of quasi-static magnetic fields at the kT-level, as well as for magnetization and accurate probing of high-energy-density samples driven by secondary powerful laser or particle beams.

Santos, J J; Giuffrida, L; Forestier-Colleoni, P; Fujioka, S; Zhang, Z; Korneev, Ph; Bouillaud, R; Dorard, S; Batani, D; Chevrot, M; Cross, J; Crowston, R; Dubois, J -L; Gazave, J; Gregori, G; d'Humières, E; Hulin, S; Ishihara, K; Kojima, S; Loyez, E; Marquès, J -R; Morace, A; Nicolaï, Ph; Peyrusse, O; Poyé, A; Raffestin, D; Ribolzi, J; Roth, M; Schaumann, G; Serres, F; Tikhonchuk, V T; Vacar, Ph; Woolsey, N

2015-01-01T23:59:59.000Z

79

Risk Management Plan Electron Beam Ion Source Project  

E-Print Network [OSTI]

Risk Management Plan for the Electron Beam Ion Source Project (EBIS) Project # 06-SC-002 at Brookhaven National Laboratory Upton, NY For the U.S. Department of Energy Office of Science Office of Nuclear Physics (SC ­ 26) #12;1. Background and References 1.1 Background The EBIS Project will manage

80

Separation of beam and electrons in the spallation neutron source H{sup -} ion source  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) requires an ion source producing an H{sup {minus}} beam with a peak current of 35mA at a 6.2 percent duty factor. For the design of this ion source, extracted electrons must be transported and dumped without adversely affecting the H{sup {minus}} beam optics. Two issues are considered: (1) electron containment transport and controlled removal; and (2) first-order H{sup {minus}} beam steering. For electron containment, various magnetic, geometric and electrode biasing configurations are analyzed. A kinetic description for the negative ions and electrons is employed with self-consistent fields obtained from a steady-state solution to Poisson`s equation. Guiding center electron trajectories are used when the gyroradius is sufficiently small. The magnetic fields used to control the transport of the electrons and the asymmetric sheath produced by the gyrating electrons steer the ion beam. Scenarios for correcting this steering by split acceleration and focusing electrodes will be considered in some detail.

Whealton, J.H.; Raridon, R.J. [Oak Ridge National Lab., TN (United States); Leung, K.N. [Lawrence Berkeley National Lab., CA (United States)

1997-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

A compact x-ray free electron laser  

SciTech Connect (OSTI)

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

Barletta, W.; Attac, M.; Cline, D.B.; Kolonko, J.; Wang, X.; Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G.; Gallardo, J.; Pellegrini, C.; Westenskow, G.

1988-09-09T23:59:59.000Z

82

Electron string ion sources for carbon ion cancer therapy accelerators  

E-Print Network [OSTI]

The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.

Boytsov, A Yu; Donets, E D; Donets, E E; Katagiri, K; Noda, K; Ponkin, D O; Ramzdorf, A Yu; Salnikov, V V; Shutov, V B

2015-01-01T23:59:59.000Z

83

Inverse free electron laser accelerator for advanced light sources  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We discuss the inverse free electron laser (IFEL) scheme as a compact high gradient accelerator solution for driving advanced light sources such as a soft x-ray free electron laser amplifier or an inverse Compton scattering based gamma-ray source. In particular, we present a series of new developments aimed at improving the design of future IFEL accelerators. These include a new procedure to optimize the choice of the undulator tapering, a new concept for prebunching which greatly improves the fraction of trapped particles and the final energy spread, and a self-consistent study of beam loading effects which leads to an energy-efficient high laser-to-beam power conversion.

Duris, J. P.; Musumeci, P.; Li, R. K.

2012-06-01T23:59:59.000Z

84

Oscillating plasma bubbles. III. Internal electron sources and sinks  

SciTech Connect (OSTI)

An internal electron source has been used to neutralize ions injected from an ambient plasma into a spherical grid. The resultant plasma is termed a plasma 'bubble.' When the electron supply from the filament is reduced, the sheath inside the bubble becomes unstable. The plasma potential of the bubble oscillates near but below the ion plasma frequency. Different modes of oscillations have been observed as well as a subharmonic and multiple harmonics. The frequency increases with ion density and decreases with electron density. The peak amplitude occurs for an optimum current and the instability is quenched at large electron densities. The frequency also increases if Langmuir probes inside the bubble draw electrons. Allowing electrons from the ambient plasma to enter, the bubble changes the frequency dependence on grid voltage. It is concluded that the net space charge density in the sheath determines the oscillation frequency. It is suggested that the sheath instability is caused by ion inertia in an oscillating sheath electric field which is created by ion bunching.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2012-08-15T23:59:59.000Z

85

Laser-Electron-Gamma-Source. Progress report, June 1984  

SciTech Connect (OSTI)

Construction of the Laser Electron Gamma Source (LEGS) began at Brookhaven in October 1983. When completed, the source will provide intense beams of monochromatic and polarized gamma rays with energies in the range of several hundreds of MeV. The planned layout of this facility with its experimental areas is shown. The gamma-ray beams will be produced by Compton backscattering uv laser light from the electrons circulating in the 2.5-3.0 GeV X-RAY storage ring of the National Synchrotron Light Source (NSLS) at BNL. The X-RAY ring is currently running with 50 mA at 1.7 GeV, and is expected to reach 2.5 GeV by November 1984. There is as yet no firm schedule for operation at 3.0 GeV, although some initial testing should be completed by the end of 1986. The availability of the 210-420 MeV LEGS beam will depend upon these 3 GeV studies.

Dowell, D.H.; Giordano, G.; LeVine, M.J.; Matone, G.; Sandorfi, A.M.; Schaerf, C.; Thorn, C.E.; Ziegler, W.

1984-01-01T23:59:59.000Z

86

Note: Simulation and test of a strip source electron gun  

SciTech Connect (OSTI)

We present simulation and test of an indirectly heated strip source electron beam gun assembly using Stanford Linear Accelerator Center (SLAC) electron beam trajectory program. The beam is now sharply focused with 3.04 mm diameter in the post anode region at 15.9 mm. The measured emission current and emission density were 1.12 A and 1.15 A/cm{sup 2}, respectively, that corresponds to power density of 11.5 kW/cm{sup 2}, at 10 kV acceleration potential. The simulated results were compared with then and now experiments and found in agreement. The gun is without any biasing, electrostatic and magnetic fields; hence simple and inexpensive. Moreover, it is now more powerful and is useful for accelerators technology due to high emission and low emittance parameters.

Iqbal, Munawar, E-mail: muniqbal.chep@pu.edu.pk [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Acedemy of Sciences, Beijing 100049 (China); Islam, G. U.; Misbah, I.; Iqbal, O. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Acedemy of Sciences, Beijing 100049 (China)

2014-06-15T23:59:59.000Z

87

Theoretical investigation of a tunable free-electron light source  

SciTech Connect (OSTI)

The concept and experimental results of a light source given in a recent paper by Adamo et al.[Phys. Rev. Lett. 103, 113901 (2009)] are very interesting and attractive. Our paper presents detailed theoretical investigations on such a light source, and our results confirm that the mechanism of the light radiation experimentally detected in the published paper is a special kind of diffraction radiation in a waveguide with nanoscale periodic structure excited by an electron beam. The numerical calculations based on our theory and digital simulations agree well with the experimental results. This mechanism of diffraction radiation is of significance in physics and optics, and may bring good opportunities for the generation of electromagnetic waves from terahertz to light frequency regimes.

Liu Shenggang; Hu Min; Zhang Yaxin; Liu Weihao; Zhang Ping; Zhou Jun [Terahertz Research Center, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-06-15T23:59:59.000Z

88

Development of a High-Brightness VHF Electron Source at LBNL  

E-Print Network [OSTI]

VHF ELECTRON SOURCE AT LBNL* S. Lidia # , F. Sannibale, J.S. Virostek, R. Wells, LBNL, Berkeley, CA, USA Abstract

Lidia, Steven M.; Sannibale, Fernando; Staples, John W.; Virostek, Steve P.; Wells, Russell P.

2008-01-01T23:59:59.000Z

89

Method of electroplating a conversion electron emitting source on implant  

DOE Patents [OSTI]

Methods for preparing an implant coated with a conversion electron emitting source (CEES) are disclosed. The typical method includes cleaning the surface of the implant; placing the implant in an activating solution comprising hydrochloric acid to activate the surface; reducing the surface by H.sub.2 evolution in H.sub.2SO.sub.4 solution; and placing the implant in an electroplating solution that includes ions of the CEES, HCl, H.sub.2SO.sub.4, and resorcinol, gelatin, or a combination thereof. Alternatively, before tin plating, a seed layer is formed on the surface. The electroplated CEES coating can be further protected and stabilized by annealing in a heated oven, by passivation, or by being covered with a protective film. The invention also relates to a holding device for holding an implant, wherein the device selectively prevents electrodeposition on the portions of the implant contacting the device.

Srivastava, Suresh C. (Setauket, NY); Gonzales, Gilbert R. (New York, NY); Adzic, Radoslav (East Setauket, NY); Meinken, George E. (Middle Island, NY)

2012-02-14T23:59:59.000Z

90

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect (OSTI)

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linac. The highly successful development of an EBIS at BNL now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based pre-injectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; ET AL.

2005-02-28T23:59:59.000Z

91

Study of an HHG-Seeded Free-Electron Laser for the LBNL Next Generation Light Source  

E-Print Network [OSTI]

Electron Laser for the LBNL Next Generation Light SourceElectron Laser for the LBNL Next Generation Light SourceBerkeley National Laboratory (LBNL). The proposed facil- ity

Thompson, Neil

2011-01-01T23:59:59.000Z

92

PUBLISHED ONLINE: 18 APRIL 2010 | DOI: 10.1038/NPHYS1638 Laser-driven amplification of soft X-rays by  

E-Print Network [OSTI]

method for parametric amplification of soft-X-ray radiation. The laser-driven amplifier is based with the conventional plasma X-ray lasers. With a simple model, we can estimate the necessary experimental conditions duration3,4 or the narrow linewidth5 . X-ray lasers (XRLs) are attractive candidates for such investi

Loss, Daniel

93

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON  

E-Print Network [OSTI]

ELECTRON STRING SOURCE OF HIGHLY CHARGED IONS: STUDIES AND THE FIRST TEST ON A SYNCHROTRON E. D, MSL, 104 05 Stockholm, Sweden Abstract Operation of an electron beam ion source (EBIS) in the reflex mode at certain conditions leads to formation of the so called electron string state of one component

94

Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL  

SciTech Connect (OSTI)

As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R and D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R and D.

Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 Caen Cedex 05 (France); Galata, A.; Porcellato, A. M.; Prete, G. F. [INFN-Laboratori Nazionali di Legnaro, Viale dell'Universita 2, 35020 Legnaro, Padova (Italy); Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T. [LPSC Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Ban, G. [LPC Caen, 6 bd Marechal Juin, 14050 Caen Cedex (France); Celona, L.; Lunney, D. [INFN-Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5a, 02 093 Warsaw (Poland); Kalvas, T. [Department of Physics, University of Jyvaeskylae, PB 35 (YFL) 40351 Jyvaeskylae (Finland); and others

2012-02-15T23:59:59.000Z

95

ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.  

SciTech Connect (OSTI)

This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linear accelerator (Linac). The highly successful development of an EBIS at Brookhaven National Laboratory (BNL) now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based preinjectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The proposed pre-injector system would also provide for a major enhancement in capability for the NASA Space Radiation Laboratory (NSRL), which utilizes heavy-ion beams from the RHIC complex. EBIS would allow for the acceleration of all important ion species for the NASA radiobiology program, such as, helium, argon, and neon which are unavailable with the present Tandem injector. In addition, the new system would allow for very rapid switching of ion species for NSRL experiments, reducing delays due to the interference with RHIC injection operations, and allowing enhanced mixed field radiation studies. The new RFQ and Linac that are used to accelerate beams from the EBIS to an energy sufficient for injection into the Booster are both very similar to existing devices already in operation at other facilities. Injection into the Booster will occur at the same location as the existing injection from the Tandem.

ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; GRANDINETTI, R.; HSEUH, H.; JAVIDFAR, A.; KPONOU, A.; LAMBIASE, R.; LESSARD, E.; LOCKEY, R.; LODESTRO, V.; MAPES, M.; MIRABELLA, D.; NEHRING, T.; OERTER, B.; PENDZICK, A.; PIKIN, A.; RAPARIA, D.; RITTER, J.; ROSER, T.; RUSSO, T.; SNYDSTRUP, L.; WILINSKI, M.; ZALTSMAN, A.; ZHANG, S.

2005-09-01T23:59:59.000Z

96

Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)  

SciTech Connect (OSTI)

In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ?300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub ?}). The detectors impulse response function was measured in situ on NIF short-pulse (?90 ps) experiments, and in off-line tests.

Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

2014-11-15T23:59:59.000Z

97

Laser Electron Gamma Source: Biennial progress report, June 1996  

SciTech Connect (OSTI)

The LEGS facility provides intense, polarized, monochromatic {gamma}-ray beams by Compton backscattering laser light from relativistic electrons circulating in the X-Ray storage ring of the National Synchrotron Light Source at Brookhaven national Laboratory. Since 1990, experiments have concentrated on single polarization observables (polarized beams on unpolarized targets) in nuclear reactions involving the {Delta} resonance. Highlights of the last two years are given. An updated status of LEGS, and recent publications, is available on the WWW via http://WWW.LEGS.BNL.GOV/{approximately}LEGS/. In 1997 a new phase of operations will begin, focusing on double-polarization measurements with circularly polarized photon beams and longitudinally polarized nucleon targets. This work requires the development of (i) a new frozen-spin hydrogen-deuteride target that provides high polarizations for both nuclear species, and (ii) a new large acceptance detector array for measuring total reaction cross sections in both neutral and charged-particle channels. Progress on these instrumentation developments is an ongoing effort of the LEGS Spin Collaboration (LSC) and is discussed in the last section of this report.

Sandorfi, A.M. [ed.

1996-09-01T23:59:59.000Z

98

RF-driven ion source with a back-streaming electron dump  

DOE Patents [OSTI]

A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

Kwan, Joe; Ji, Qing

2014-05-20T23:59:59.000Z

99

Production of Neutrinos and Secondary Electrons in Cosmic Sources  

E-Print Network [OSTI]

We study the individual contribution to secondary lepton production in hadronic interactions of cosmic rays (CRs) including resonances and heavier secondaries. For this purpose we use the same ethodology discussed earlier \\cite{Huang07}, namely the Monte Carlo particle collision code DPMJET3.04 to determine the multiplicity spectra of various secondary particles with leptons as the final decay states, that result from inelastic collisions of cosmic-ray protons and Helium nuclei with the interstellar medium of standard composition. By combining the simulation results with parametric models for secondary particle (with resonances included) for incident cosmic-ray energies below a few GeV, where DPMJET appears unreliable, we thus derive production matrices for all stable secondary particles in cosmic-ray interactions with energies up to about 10 PeV. We apply the production matrices to calculate the radio synchrotron radiation of secondary electrons in a young shell-type SNR, RX J1713.7-3946, which is a measure of the age, the spectral index of hadronic cosmic rays, and most importantly the magnetic field strength. We find that the multi-mG fields recently invoked to explain the X-ray flux variations are unlikely to extend over a large fraction of the radio-emitting region, otherwise the spectrum of hadronic cosmic rays in the energy window 0.1-100 GeV must be unusually hard. We also use the production matrices to calculate the muon event rate in an IceCube-like detector that are induced by muon neutrinos from high-energy $\\gamma$-ray sources such as RX J1713.7-3946, Vela Jr. and MGRO J2019+37. At muon energies of a few TeV, or in other word, about 10 TeV neutrino energy, an accumulation of data over about five to ten years would allow testing the hadronic origin of TeV $\\gamma$-rays.

C. -Y. Huang; M. Pohl

2008-01-23T23:59:59.000Z

100

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures  

SciTech Connect (OSTI)

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Byer, Robert L.

2013-11-07T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Laser-driven deflection arrangements and methods involving charged particle beams  

DOE Patents [OSTI]

Systems, methods, devices and apparatus are implemented for producing controllable charged particle beams. In one implementation, an apparatus provides a deflection force to a charged particle beam. A source produces an electromagnetic wave. A structure, that is substantially transparent to the electromagnetic wave, includes a physical structure having a repeating pattern with a period L and a tilted angle .alpha., relative to a direction of travel of the charged particle beam, the pattern affects the force of the electromagnetic wave upon the charged particle beam. A direction device introduces the electromagnetic wave to the structure to provide a phase-synchronous deflection force to the charged particle beam.

Plettner, Tomas (San Ramon, CA); Byer, Robert L. (Stanford, CA)

2011-08-09T23:59:59.000Z

102

Apparatus and method for compensating for electron beam emittance in synchronizing light sources  

DOE Patents [OSTI]

A focused optical beam is used to change the path length of the core electrons in electron light sources thereby boosting their efficiency of conversion of electron beam energy to light. Both coherent light in the free electron laser and incoherent light in the synchrotron is boosted by this technique. By changing the path length of the core electrons by the proper amount, the core electrons are caused to stay in phase with the electrons in the outer distribution of the electron beam. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.

Neil, George R. (Williamsburg, VA)

1996-01-01T23:59:59.000Z

103

Apparatus and method for compensating for electron beam emittance in synchronizing light sources  

DOE Patents [OSTI]

A focused optical beam is used to change the path length of the core electrons in electron light sources thereby boosting their efficiency of conversion of electron beam energy to light. Both coherent light in the free electron laser and incoherent light in the synchrotron is boosted by this technique. By changing the path length of the core electrons by the proper amount, the core electrons are caused to stay in phase with the electrons in the outer distribution of the electron beam. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron. 4 figs.

Neil, G.R.

1996-07-30T23:59:59.000Z

104

Laser-driven formation of a high-pressure phase in amorphous silica  

SciTech Connect (OSTI)

A combination of electron diffraction and infrared reflectance measurements shows that synthetic silica transforms partially into stishovite under high-intensity (GW/cm2) laser irradiation, probably by the formation of a dense ionized plasma above the silica surface. During the transformation the silicon coordination changes from four-fold to six-fold and the silicon-oxygen bond changes from mostly covalent to mostly ionic, such that optical properties of the transformed material differ significantly from those of the original glass. This phase transformation offers one suitable mechanism by which laser-induced damage grows catastrophically once initiated, thereby dramatically shortening the service lifetime of optics used for high-power photonics applications such as inertial confinement fusion.

Salleo, Alberto; Taylor, Seth T.; Martin, Michael C.; Panero, Wendy R.; Jeanloz, Raymond; Genin, Francois Y.; Sands, Timothy

2002-05-31T23:59:59.000Z

105

Single Atom Electron and Ion Sources and Their Applications  

E-Print Network [OSTI]

- energy electron point projection microscope, PPM) (37, 38) 1. (shadow microscopy) (shadow image-walled carbon nanotubes, SWNTs) (111) (pizeo-scanner) X- Y-Z (scanning tunneling microscope) 3. (a on the screen (mm) Intensity(Arb.Units) (c) (a) (b) Q FWHM P (a) (b)Dd sample holder detector-MCP #12;13 98

106

Accelerated Electrons as the Source of Auroral Kilometric Radiation R. J. Strangeway  

E-Print Network [OSTI]

Accelerated Electrons as the Source of Auroral Kilometric Radiation R. J. Strangeway Institute-04, presented at the 2nd EGS Alfvén Conference on Auroral Particle Acceleration, 3-7 May 1999, Stockholm, Sweden) have confirmed that Auroral Kilometric Radiation (AKR) is generated by the accelerated electrons

Strangeway, Robert J.

107

Hybrid single-electron transistor as a source of quantized electric current  

E-Print Network [OSTI]

LETTERS Hybrid single-electron transistor as a source of quantized electric current JUKKA P. PEKOLA of a hybrid normal-metal­ superconductor turnstile in the form of a one-island single- electron transistor currents in the nano-ampere range but their accuracy is still limited. Surprisingly, a simple hybrid single

Loss, Daniel

108

On the role of electron energy distribution function in double frequency heating of electron cyclotron resonance ion source plasmas  

SciTech Connect (OSTI)

Double frequency heating (DFH) is a tool to improve the output of highly charged ions particularly from modern electron cyclotron resonance ion source installations with very high RF-frequencies. In order to gain information on the DFH-mechanism and on the role of the lower injected frequency we have carried out a series of dedicated experiments where we have put emphasis on the creation of a discrete resonance surface also for this lower frequency. Our well-established method of inserting an emissive MD (metal-dielectric) liner into the plasma chamber of the source is used in these experiments as a tool of investigation. In this way, the electron temperature and density for both ECR zones is increased in a controlled manner, allowing conclusions on the role of the change of the electron-energy-distribution function with and without DFH.

Schachter, L., E-mail: lsch@tandem.nipne.ro; Dobrescu, S. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania)] [National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Stiebing, K. E. [Institut für Kernphysik der J. W. Goethe Universität, Frankfurt/Main (Germany)] [Institut für Kernphysik der J. W. Goethe Universität, Frankfurt/Main (Germany)

2014-02-15T23:59:59.000Z

109

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources  

DOE Patents [OSTI]

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Alton, G.D.

1998-11-24T23:59:59.000Z

110

Development of a high average current polarized electron source with long cathode operational lifetime  

SciTech Connect (OSTI)

Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and have often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2?105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.

C. K. Sinclair; P. A. Adderley; B. M. Dunham; J. C. Hansknecht; P. Hartmann; M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; M. Steigerwald

2007-02-01T23:59:59.000Z

111

ELECTRON-CAPTURE SUPERNOVAE AS SOURCES OF {sup 60}Fe  

SciTech Connect (OSTI)

We investigate the nucleosynthesis of the radionuclide {sup 60}Fe in electron-capture supernovae (ECSNe). The nucleosynthetic results are based on a self-consistent, two-dimensional simulation of an ECSN as well as models in which the densities are systematically increased by some factors (low-entropy models). {sup 60}Fe is found to be appreciably made in neutron-rich ejecta during the nuclear quasi-equilibrium phase with greater amounts being produced in the lower-entropy models. Our results, combining them with the yields of core-collapse supernovae in the literature, suggest that ECSNe account for at least 4%-30% of live {sup 60}Fe in the Milky Way. ECSNe co-produce neutron-rich isotopes, {sup 48}Ca, {sup 50}Ti, {sup 54}Cr, some light trans-iron elements, and possibly weak r-process elements including some radionuclides such as {sup 93}Zr, {sup 99}Tc, and {sup 107}Pd, whose association with {sup 60}Fe might have been imprinted in primitive meteorites or in the deep ocean crust on the Earth.

Wanajo, Shinya [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Janka, Hans-Thomas; Mueller, Bernhard, E-mail: shinya.wanajo@nao.ac.jp [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

2013-09-01T23:59:59.000Z

112

Electron Bunch Profile Reconstruction in the Few fs Regime using Coherent Smith-Purcell Radiation  

SciTech Connect (OSTI)

Advanced accelerators for fourth generation light sources based on high brightness linacs or laser-driven wakefield accelerators will operate with intense, highly relativistic electron bunches that are only a few fs long. Diagnostic techniques for the determination of temporal profile of such bunches are required to be non invasive, single shot, economic and with the required resolution in the fs regime. The use of a radiative process such as coherent Smith-Purcell radiation (SPR), is particularly promising with this respect. In this technique the beam is made to radiate a small amount of electromagnetic radiation and the temporal profile is reconstructed from the measured spectral distribution of the radiation. We summarise the advantages of SPR and present the design parameters and preliminary results of the experiments at the FACET facility at SLAC. We also discuss a new approach to the problem of the recovery of the 'missing phase', which is essential for the accurate reconstruction of the temporal bunch profile.

Bartolini, R.; /Oxford U., JAI /Diamond Light Source /SLAC; Clarke, C.; /SLAC; Delerue, N; /Oxford U., JAI /Diamond Light Source /SLAC; Doucas, G; Reichold, A; /Oxford U., JAI

2012-06-20T23:59:59.000Z

113

Simulation and optimization of a 10 A electron gun with electrostatic compression for the electron beam ion source  

SciTech Connect (OSTI)

Increasing the current density of the electron beam in the ion trap of the Electron Beam Ion Source (EBIS) in BNL's Relativistic Heavy Ion Collider facility would confer several essential benefits. They include increasing the ions' charge states, and therefore, the ions' energy out of the Booster for NASA applications, reducing the influx of residual ions in the ion trap, lowering the average power load on the electron collector, and possibly also reducing the emittance of the extracted ion beam. Here, we discuss our findings from a computer simulation of an electron gun with electrostatic compression for electron current up to 10 A that can deliver a high-current-density electron beam for EBIS. The magnetic field in the cathode-anode gap is formed with a magnetic shield surrounding the gun electrodes and the residual magnetic field on the cathode is (5 Division-Sign 6) Gs. It was demonstrated that for optimized gun geometry within the electron beam current range of (0.5 Division-Sign 10) A the amplitude of radial beam oscillations can be maintained close to 4% of the beam radius by adjusting the injection magnetic field generated by a separate magnetic coil. Simulating the performance of the gun by varying geometrical parameters indicated that the original gun model is close to optimum and the requirements to the precision of positioning the gun elements can be easily met with conventional technology.

Pikin, A.; Beebe, E. N.; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

2013-03-15T23:59:59.000Z

114

Neutron source in the MCNPX shielding calculating for electron accelerator driven facility  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Inst. of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of an experimental neutron source facility. It is an accelerator driven system (ADS) utilizing a subcritical assembly driven by electron accelerator. The facility will be utilized for performing basic and applied nuclear researches, producing medical isotopes, and training young nuclear specialists. Monte Carlo code MCNPX has been utilized as a design tool due to its capability to transport electrons, photons, and neutrons at high energies. However the facility shielding calculations with MCNPX need enormous computational resources and the small neutron yield per electron makes sampling difficulty for the Monte Carlo calculations. A method, based on generating and utilizing neutron source file, was proposed and tested. This method reduces significantly the required computer resources and improves the statistics of the calculated neutron dose outside the shield boundary. However the statistical errors introduced by generating the neutron source were not directly represented in the results, questioning the validity of this methodology, because an insufficiently sampled neutron source can cause error on the calculated neutron dose. This paper presents a procedure for the validation of the generated neutron source file. The impact of neutron source statistic on the neutron dose is examined by calculating the neutron dose as a function of the number of electron particles used for generating the neutron source files. When the value of the calculated neutron dose converges, it means the neutron source has scored sufficient records and statistic does not have apparent impact on the calculated neutron dose. In this way, the validity of neutron source and the shield analyses could be verified. (authors)

Zhong, Z.; Gohar, Y. [Nuclear Engineering Div., Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2012-07-01T23:59:59.000Z

115

Electron emission in a source-collector sheath system: A kinetic study  

SciTech Connect (OSTI)

The classical source-collector sheath system describes a plasma that forms between a Maxwellian source and an absorbing wall. The plasma is assumed to be collisionless and without ionization. Two distinct areas are being formed: the collector sheath, an ion-rich region in contact with the absorbing boundary, and the source sheath, which is an electron-rich area near the Maxwellian source. In this work, we study a modified version of the classical source-collector sheath system, where the wall is no longer absorbing but emits electrons. As a result, we have two different types of collector sheath, one where a potential well is formed and one without a potential well. We examine the effect of electron emission for a range of conditions for the plasma and the emitted electrons. In the first part of this work, we study the problem analytically, and in the second, using our kinetic Vlasov code, Yggdrasil. The simulation results are in very good agreement with the predictions of our theoretical model.

Rizopoulou, N., E-mail: nikoleta.rizopoulou06@imperial.ac.uk; Coppins, M.; Bacharis, M. [Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom); Robinson, A. P. L. [Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom)

2014-10-15T23:59:59.000Z

116

Note: Production of a mercury beam with an electron cyclotron resonance ion source  

SciTech Connect (OSTI)

An electron cyclotron resonance ion source has been utilized to produce mercury beams with intensities of 4.5 e?A of {sup 202}Hg{sup 29+} and 3.0 e?A of {sup 202}Hg{sup 31+} from natural abundance mercury metal. The production technique relies on the evaporation of liquid mercury into the source plasma vacuum region and utilizes elemental mercury instead of a volatile organic compound as the neutral feed material.

Vondrasek, R.; Pardo, R.; Scott, R. [Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)] [Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)

2013-11-15T23:59:59.000Z

117

Production of energetic neutral particles and low energy electrons from four anode rods ion source  

SciTech Connect (OSTI)

The factors affecting the energetic neutral current, the low energy electron current, and the positive ion current emerging from a four-anode-rods ion source have been studied using argon gas. The neutral and electron current were measured using a simple, new technique. It was found that the energetic neutral current and the electron current depend on the positive ion current and the gas pressure. The ratio of the neutral and electron current to the positive ion current increases by increasing the gas pressure. Also it was found that at a pressure equal to 9 × 10{sup ?4} mmHg, the ratio of the neutral to the positive ion current reaches 2.34 while the ratio of the electron current to the positive ion current reaches 1.7.

Mostafa, O. A.; El-Khabeary, H.; Abdel Reheem, A. M. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority P.N.13759, Inchas, Cairo (Egypt)] [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority P.N.13759, Inchas, Cairo (Egypt)

2013-11-15T23:59:59.000Z

118

Ultraviolet stimulated electron source for use with low energy plasma instrument calibration  

E-Print Network [OSTI]

We report the development of a versatile, compact, low to medium energy electron source. A collimated, monoenergetic beam of electrons, up to 50 mm in diameter, is produced with energies ranging from 0.03 to 30 keV. A uniform electron beam profile is generated by illuminating a metal cathode plate with a near ultraviolet (UV) light emitting diode (LED). A parallel electric field accelerates the electrons away from the cathode plate towards a grounded grid. The beam intensity can be controlled from 10 - 10^9 electrons cm-2 s-1 and the angular divergence of the beam is less than 1 degree FWHM for energies greater than 1 keV.

Henderson, Kevin; Funsten, Herb; MacDonald, Elizabeth

2011-01-01T23:59:59.000Z

119

Ultraviolet stimulated electron source for use with low energy plasma instrument calibration  

SciTech Connect (OSTI)

We have developed and demonstrated a versatile, compact electron source that can produce a mono-energetic electron beam up to 50 mm in diameter from 0.1 to 30 keV with an energy spread of <10 eV. By illuminating a metal cathode plate with a single near ultraviolet light emitting diode, a spatially uniform electron beam with 15% variation over 1 cm{sup 2} can be generated. A uniform electric field in front of the cathode surface accelerates the electrons into a beam with an angular divergence of <1 Degree-Sign at 1 keV. The beam intensity can be controlled from 10 to 10{sup 9} electrons cm{sup -2} s{sup -1}.

Henderson, Kevin; Harper, Ron; Funsten, Herb; MacDonald, Elizabeth [Space Science and Applications, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-07-15T23:59:59.000Z

120

Field-Emission Properties in the ERL-Electron Source Vaibhav Kukreja  

E-Print Network [OSTI]

Field-Emission Properties in the ERL-Electron Source Vaibhav Kukreja Department of Physics, Cornell field emission poses many risks to the function and the structure of the gun. We have tested five electrodes with different composition and surface treatment. In this paper, we will discuss their emission

Hoffstaetter, Georg

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Are energetic electrons in the solar wind the source of the outer radiation belt?  

E-Print Network [OSTI]

Are energetic electrons in the solar wind the source of the outer radiation belt? Xinlin Li,1 D. N. Mewaldt6 Abstract. Using data from WIND, SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer), and the Los Alamos National Laboratory (LANL) sensors onboard geostationary satellites, we investigate

Li, Xinlin

122

Source: "Careers for Electrical Engineers and Computer Scientists" Institute of Electrical and Electronics Engineers HISTORICAL OVERVIEW  

E-Print Network [OSTI]

Source: "Careers for Electrical Engineers and Computer Scientists" © Institute of Electrical and Electronics Engineers HISTORICAL OVERVIEW PREPARED BY THE IEEE HISTORY CENTER RUTGERS UNIVERSITY ELECTRICITY IN THE 1880s The organization of the electrical engineering profession in America in the1880s

New Hampshire, University of

123

LITHIUM PLASMA SOURCES FOR ACCELERATION AND FOCUSING OF ULTRA-RELATIVISTIC ELECTRON BEAMSi  

E-Print Network [OSTI]

LITHIUM PLASMA SOURCES FOR ACCELERATION AND FOCUSING OF ULTRA-RELATIVISTIC ELECTRON BEAMSi P beam focusing (plasma lens). The Li vapor with a density in the 2Ã?1015 cm-3 range is produced in a heat to a focusing strength in excess of 6Ã?105 G/cm. A shorter section of plasma (L25 cm) can be used as an effective

124

The Most Likely Sources of High Energy Cosmic-Ray Electrons in Supernova Remnants  

E-Print Network [OSTI]

Evidences of non-thermal X-ray emission and TeV gamma-rays from the supernova remnants (SNRs) has strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Due to these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older than ~10^5 yr, cannot reach the solar system. We investigated the cosmic-ray electron spectrum observed in the solar system using an analytical method, and considered several candidate sources among nearby SNRs which may contribute to the high energy electron flux. Especially, we discuss the effects for the release time from SNRs after the explosion, as well as the deviation of a source spectrum from a simple power-law. From this calculation, we found that some nearby sources such as the Vela, Cygnus Loop, or Monogem could leave unique signatures in the form of identifiable structure in the energ...

Kobayashi, T; Yoshida, K; Nishimura, J

2004-01-01T23:59:59.000Z

125

Mass spectrometer with electron source for reducing space charge effects in sample beam  

DOE Patents [OSTI]

A mass spectrometer includes an ion source which generates a beam including positive ions, a sampling interface which extracts a portion of the beam from the ion source to form a sample beam that travels along a path and has an excess of positive ions over at least part of the path, thereby causing space charge effects to occur in the sample beam due to the excess of positive ions in the sample beam, an electron source which adds electrons to the sample beam to reduce space charge repulsion between the positive ions in the sample beam, thereby reducing the space charge effects in the sample beam and producing a sample beam having reduced space charge effects, and a mass analyzer which analyzes the sample beam having reduced space charge effects.

Houk, Robert S.; Praphairaksit, Narong

2003-10-14T23:59:59.000Z

126

Investigation of an electron beam evaporative source: Part 1, Theory; Part 2, Measurements  

SciTech Connect (OSTI)

A theory for evaluating the performance parameters of linear electron beam evaporative source is presented. The electron beam is considered to be generated from a linear gun and its trajectory is curved by a uniform magnetic field onto a target. A model has been developed to estimate the trajectory of the electron beam. The performance of the electron gun is characterized by two coefficients: {alpha}, the divergence effect of the beam as it enters into the electric field free space region, and {Beta}, the space charge parameter, which is proportional to the magnitude of the current density of the beam. These two parameters determine the location (angular position) of the beam waist and the current density at the target. In addition, neutralization of the electron space charge by vapor ions generated near the target is considered. A discussion is also given of the shape of the depression in the surface of the molten metal, which is due to the pressure on the surface associated with the momentum recoil from the evaporative vapor flux. By relating the characteristic depth and width of the depression to magnitude and the shape of the pressure profile, useful analytical and numerical results are presented for a given pressure profile. The implication of the results for the design of electron beam evaporative sources are also discussed. Measurements are discussed a the end of the paper. 11 refs., 15 figs.

Sze, J.S.; Self, S.A. (Lawrence Livermore National Lab., CA (USA))

1989-09-14T23:59:59.000Z

127

Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source  

SciTech Connect (OSTI)

A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20–40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, ?2 to ?4 kV, and 0 kV, respectively. The total ion beam current of 30–40 mA is recorded on Faraday cup at 40 keV of beam energy at 600–1000 W of microwave power, 800–1000 G axial magnetic field and (1.2–3.9) × 10{sup ?3} mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

Roychowdhury, P., E-mail: pradipr@barc.gov.in; Mishra, L.; Kewlani, H.; Mittal, K. C. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Patil, D. S. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2014-03-15T23:59:59.000Z

128

Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part I. Electronic brachytherapy source  

SciTech Connect (OSTI)

Purpose: Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR){sup 192}Ir sources, as well as electronic brachytherapy sources. Part I of this paper will discuss the applicators used with electronic brachytherapy sources; Part II will discuss those used with HDR {sup 192}Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics including depth dose and surface dose distributions have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. Existing dosimetry protocols available from the AAPM bookend the cross-over characteristics of a traditional brachytherapy source (as described by Task Group 43) being implemented as a low-energy superficial x-ray beam (as described by Task Group 61) as observed with the surface applicators of interest. Methods: This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and{sup 192}Ir sources (Part II). Air-kerma rate measurements for the electronic brachytherapy sources were completed with an Attix Free-Air Chamber, as well as several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose measurements of the surface dose distributions and characteristic depth dose curves were completed in-phantom. Results: Theoretical dose distributions and depth dose curves were generated for each applicator and agreed well with the measured values. A method of output verification was created that allows users to determine the applicator-specific dose to water at the treatment surface based on a measured air-kerma rate. Conclusions: The novel output verification methods described in this work will reduce uncertainties in dose delivery for treatments with these kinds of surface applicators, ultimately improving patient care.

Fulkerson, Regina K., E-mail: rmkenned@gmail.com; Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin 53705 (United States)

2014-02-15T23:59:59.000Z

129

Potential applications of a new microwave ECR (electron cyclotron resonance) multicusp plasma ion source  

SciTech Connect (OSTI)

A new microwave electron cyclotron resonance (ECR) multicusp plasma ion source using two ECR plasma production regions and multicusp plasma confinement has been developed at Oak Ridge National Laboratory. This source has been operated to produce uniform and dense plasmas over large areas of 300 to 400 cm{sup 2}. The plasma source has been operated with continuous argon gas feed and pulsed microwave power. The discharge initiation phenomena and plasma properties have been investigated and studied as functions of discharge parameters. Together with the discharge characteristics observed, a hypothetical discharge mechanism for this plasma source is reported and discussed. Potential applications, including plasma and ion-beam processing for manufacturing advanced microelectronics and for space electric propulsion, are discussed. 7 refs., 6 figs.

Tsai, C.C.

1990-01-01T23:59:59.000Z

130

Langmuir probe diagnostics of plasma in high current electron cyclotron resonance proton ion source  

SciTech Connect (OSTI)

A high current Electron Cyclotron Resonance (ECR) proton ion source has been developed for low energy high intensity proton accelerator at Bhabha Atomic Research Centre. Langmuir probe diagnostics of the plasma generated in this proton ion source is performed using Langmuir probe. The diagnostics of plasma in the ion source is important as it determines beam parameters of the ion source, i.e., beam current, emittance, and available species. The plasma parameter measurement in the ion source is performed in continuously working and pulsed mode using hydrogen as plasma generation gas. The measurement is performed in the ECR zone for operating pressure and microwave power range of 10{sup ?4}–10{sup ?3} mbar and 400–1000 W. An automated Langmuir probe diagnostics unit with data acquisition system is developed to measure these parameters. The diagnostics studies indicate that the plasma density and plasma electron temperature measured are in the range 5.6 × 10{sup 10} cm{sup ?3} to 3.8 × 10{sup 11} cm{sup ?3} and 4–14 eV, respectively. Using this plasma, ion beam current of tens of mA is extracted. The variations of plasma parameters with microwave power, gas pressure, and radial location of the probe have been studied.

Roychowdhury, P.; Kewlani, H.; Mishra, L.; Mittal, K. C. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Patil, D. S. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2013-07-15T23:59:59.000Z

131

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active Power Filter Based on  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 53, NO. 2, APRIL 2006 477 Voltage-Source Active MODERN power electronics have contributed a great deal to the development of new powerful applications in line currents, which ends up distorting the voltage waveforms. Some power electronics applications

Catholic University of Chile (Universidad Católica de Chile)

132

Growth of silicon-on-insulator films using a line-source electron beam  

SciTech Connect (OSTI)

A swept line-source electron beam has been used to study unseeded Si-on-insulator crystallization at beam scan speeds of 150 to 1500 cm/s. For a particular sample configuration a maximum linear crystallization velocity of approx. 350 cm/s was observed. At higher sweep speeds, competing nucleation occurred at intervals across the film. Both the limit in crystallization velocity and the intervals between nucleation are tentatively explained by a simple model.

Knapp, J.A.; Picraux, S.T.

1982-01-01T23:59:59.000Z

133

An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources  

SciTech Connect (OSTI)

An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10{sup 10} cm{sup ?3} to 1 × 10{sup 11} cm{sup ?3}, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10{sup 18} atoms/s for aluminum, which meets the demand for the production of a milliampere Al{sup +} ion beam.

Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany)] [Fraunhofer Institute for Electron Beam and Plasma Technology, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany)] [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Silze, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)] [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

2014-05-15T23:59:59.000Z

134

DEVELOPMENT OF A COMPACT PHOTO-INJECTOR WITH RFFOCUSING LENS FOR SHORT PULSE ELECTRON SOURCE APPLICATION  

SciTech Connect (OSTI)

For development of compact ultrafast electron source system, we are currently designing a short-pulse RF-gun with RF focusing structure by means of a series of comprehensive modeling analysis processes. EM design of a 2.5 cell resonant cavity with input coupler, acceleration dynamics of photo-emitted electron bunch, EM design of RF-lens with input coupler, and phasespace analysis of focused electron bunch are systematically examined with multi-physics simulators. All the features of the 2.856 GHz cavity geometry were precisely engineered for acceleration energies ranging from 100 keV to 500 keV (safety limited) to be powered by our 5 MW S-band klystron. The klystron (Thales TH2163) and modulator system (ScandiNova K1 turnkey system) were successfully installed and tested. Performance tests of the klystron system show peak output power > 5 MW, as per operation specifications. At the quasi-relativistic energies, the electron source is capable of generating 100fC – 1 pC electron bunch with pulse duration close to 30 fs – 1 ps and transverse size of a few hundred microns. PIC simulations have shown that the electron bunch undergoes fast RF acceleration, rapidly reaching the desired energies, which can be controlled by tuning RF injection phase and input driving power. It has been shown that it is possible to also focus/compress the bunch longitudinally using a RF-lens, which would allow us to control the temporal resolution of the system as well. While our primary analysis has been performed on a 2.5 cell design, we are also looking into half-cell (single cavity) design that is expected to provide the same range of beam energy with a simple configuration.

Grabenhofer, Alexander [Northern Illinois University; Eaton, Douglas W. [ScandiNova systems AB, Uppsala, Sweden

2013-09-01T23:59:59.000Z

135

Roadmap for the design of a superconducting electron cyclotron resonance ion source for Spiral2  

SciTech Connect (OSTI)

A review of today achieved A/Q = 3 heavy ions beams is proposed. The daily operation A/Q = 3 ion beam intensities expected at Spiral2 are at the limit or above best record 3rd generation electron cyclotron resonance ion source (ECRIS) intensities. The necessity to build a new fully superconducting to fulfill these requirements is outlined. A discussion on the volume of the future source is proposed and the minimum value of 12 liters is derived. An analysis of the x-ray absorption superconducting ECRIS is presented based on VENUS experimental data and geometry. This study underlines the necessity to include a complete x-ray study at the time of source conception. The specifications foreseen for the new ECRIS are presented, followed with the roadmap for the design.

Thuillier, T.; Angot, J.; Lamy, T. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des martyrs 38026 Grenoble cedex (France); Barue, C.; Canet, C.; Leherissier, P.; Lemagnen, F.; Maunoury, L. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Peaucelle, C. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, Universite de Lyon 1, CNRS/IN2P3, Villeurbanne (France)

2012-02-15T23:59:59.000Z

136

Facility for fast neutron irradiation tests of electronics at the ISIS spallation neutron source  

SciTech Connect (OSTI)

The VESUVIO beam line at the ISIS spallation neutron source was set up for neutron irradiation tests in the neutron energy range above 10 MeV. The neutron flux and energy spectrum were shown, in benchmark activation measurements, to provide a neutron spectrum similar to the ambient one at sea level, but with an enhancement in intensity of a factor of 10{sup 7}. Such conditions are suitable for accelerated testing of electronic components, as was demonstrated here by measurements of soft error rates in recent technology field programable gate arrays.

Andreani, C.; Pietropaolo, A.; Salsano, A. [Centro NAST, Universita degli Studi di Roma Tor Vergata (Italy); Gorini, G.; Tardocchi, M. [Dipartimento di Fisica 'G. Occhialini', Universita degli Studi di Milano-Bicocca (Italy); Paccagnella, A.; Gerardin, S. [Dipartimento di Ingegneria dell'Informazione, Universita di Padova (Italy); Frost, C. D.; Ansell, S. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Platt, S. P. [School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston, Lancs. PR1 2HE (United Kingdom)

2008-03-17T23:59:59.000Z

137

Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University  

SciTech Connect (OSTI)

In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C{sub 60} using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Minezaki, H.; Ishihara, S. [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)] [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan); Muramatsu, M.; Kitagawa, A.; Drentje, A. G. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan)] [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary)] [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary); Asaji, T. [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan)] [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan)] [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan) [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)

2014-02-15T23:59:59.000Z

138

Silicon-on-insulator structures formed by a line-source electron beam: Experiment and theory  

SciTech Connect (OSTI)

A line-source electron beam has been used to melt and recrystallize isolated Si layers to form Si-on-insulator structures. Heat flow calculations for these layered structures have been developed which correctly predict the observed recrystallization. Using sample sweep speeds of 100--600 cm/s and peak power densities up to 75 kW/cm/sup 2/ in the 1 x 20-mm beam, we have obtained single-crystal areas as large as 50 x 350 ..mu..m. Seed openings to the substrate are used to control the orientation of the regrowth and the heat flow in the recrystallization film.

Knapp, J.A.

1985-10-01T23:59:59.000Z

139

Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source  

E-Print Network [OSTI]

A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.

Asaji, T; Uchida, T; Minezaki, H; Ishihara, S; Racz, R; Muramatsu, M; Biri, S; Kitagawa, A; Kato, Y; Yoshida, Y

2015-01-01T23:59:59.000Z

140

Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University  

E-Print Network [OSTI]

In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C60 using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

Uchida, T; Ishihara, S; Muramatsu, M; Racz, R; Asaji, T; Kitagawa, A; Kato, Y; Biri, S; Drentje, A G; Yoshida, Y

2015-01-01T23:59:59.000Z

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141

Philips Light Sources & Electronics is Developing an Efficient, Smaller, Cost-Effective Family of LED Drivers  

Broader source: Energy.gov [DOE]

With the help of DOE funding, Philips Light Sources & Electronics is developing a new family of LED drivers that are more efficient and cost-effective as well as smaller in size than currently available drivers. The new drivers are switch-mode power supplies that are similar to today's drivers, but with an improved design. In addition, they have a different topology—boost plus LLC—for wattages of 40W and above, but they retain the commonly used flyback topology at lower wattages.

142

Estimation of the electron density and radiative energy losses in a calcium plasma source based on an electron cyclotron resonance discharge  

SciTech Connect (OSTI)

The parameters of a calcium plasma source based on an electron cyclotron resonance (ECR) discharge were calculated. The analysis was performed as applied to an ion cyclotron resonance system designed for separation of calcium isotopes. The plasma electrons in the source were heated by gyrotron microwave radiation in the zone of the inhomogeneous magnetic field. It was assumed that, in such a combined trap, the energy of the extraordinary microwave propagating from the high-field side was initially transferred to a small group of resonance electrons. As a result, two electron components with different transverse temperatures-the hot resonance component and the cold nonresonance component-were created in the plasma. The longitudinal temperatures of both components were assumed to be equal. The entire discharge space was divided into a narrow ECR zone, where resonance electrons acquired transverse energy, and the region of the discharge itself, where the gas was ionized. The transverse energy of resonance electrons was calculated by solving the equations for electron motion in an inhomogeneous magnetic field. Using the law of energy conservation and the balance condition for the number of hot electrons entering the discharge zone and cooled due to ionization and elastic collisions, the density of hot electrons was estimated and the dependence of the longitudinal temperature T{sub e Parallel-To} of the main (cold) electron component on the energy fraction {beta} lost for radiation was obtained.

Potanin, E. P., E-mail: potanin@imp.kiae.ru; Ustinov, A. L. [National Research Centre Kurchatov Institute (Russian Federation)

2013-06-15T23:59:59.000Z

143

VOLUME 87, NUMBER 8 P H Y S I C A L R E V I E W L E T T E R S 20 AUGUST 2001 Investigation of Ultrafast Laser-Driven Radiative Blast Waves  

E-Print Network [OSTI]

. This is believed to be due to the stabilizing effect of a relatively thick blast wave shell resulting in part from of Ultrafast Laser-Driven Radiative Blast Waves M.J. Edwards,1 A. J. MacKinnon,1 J. Zweiback,1 K. Shigemori,2 D blast waves produced by the deposition of femtosecond laser pulses in gas jets. In high-Z gases

Ditmire, Todd

144

Design and dosimetric characteristics of a new endocavitary contact radiotherapy system using an electronic brachytherapy source  

SciTech Connect (OSTI)

Purpose: To present design aspects and acceptance tests performed for clinical implementation of electronic brachytherapy treatment of early stage rectal adenocarcinoma. A dosimetric comparison is made between the historically used Philips RT-50 unit and the newly developed Axxent{sup Registered-Sign} Model S700 electronic brachytherapy source manufactured by Xoft (iCad, Inc.). Methods: Two proctoscope cones were manufactured by ElectroSurgical Instruments (ESI). Two custom surface applicators were manufactured by Xoft and were designed to fit and interlock with the proctoscope cones from ESI. Dose rates, half value layers (HVL), and percentage depth dose (PDD) measurements were made with the Xoft system and compared to historical RT-50 data. A description of the patient treatment approach and exposure rates during the procedure is also provided. Results: The electronic brachytherapy system has a lower surface dose rate than the RT-50. The dose rate to water on the surface from the Xoft system is approximately 2.1 Gy/min while the RT-50 is 10-12 Gy/min. However, treatment times with Xoft are still reasonable. The HVLs and PDDs between the two systems were comparable resulting in similar doses to the target and to regions beyond the target. The exposure rate levels around a patient treatment were acceptable. The standard uncertainty in the dose rate to water on the surface is approximately {+-}5.2%. Conclusions: The Philips RT-50 unit is an out-of-date radiotherapy machine that is no longer manufactured with limited replacement parts. The use of a custom-designed proctoscope and Xoft surface applicators allows delivery of a well-established treatment with the ease of a modern radiotherapy device. While the dose rate is lower with the use of Xoft, the treatment times are still reasonable. Additionally, personnel may stand farther away from the Xoft radiation source, thus potentially reducing radiation exposure to the operator and other personnel.

Richardson, Susan; Garcia-Ramirez, Jose; Lu Wei; Myerson, Robert J.; Parikh, Parag [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

2012-11-15T23:59:59.000Z

145

Electron Beam Energy Chirp Control with a Rectangular Corrugated Structure at the Linac Coherent Light Source  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar to the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.

Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa

2015-01-30T23:59:59.000Z

146

ELECTRON CYCLOTRON RESONANCE DISCHARGE AS A SOURCE FOR HYDROGEN AND DEUTERIUM IONS PRODUCTION  

E-Print Network [OSTI]

of controlled thermonuclear fusion. Plasma sources are acknowledged to be among the most efficient sources

Boyer, Edmond

147

Si-on-Insulator formation using a line-source electron beam  

SciTech Connect (OSTI)

A line-source electron beam has been used to melt and recrystallize isolated Si layers to form Si-on-Insulator structures, and the process is simulated by heat flow calculations. Using sample sweep speeds of 100 to 600 cm/s and peak power densities up to 75 kW/cm/sup 2/ in the 1 x 20 mm beam, we have obtained single-crystal areas as large as 50 x 350 ..mu..m. Seed openings to the substrate are used to control the orientation of the regrowth and the heat flow in the recrystallizing film. A finite-element heat flow code has been developed which correctly simulates the experimental results and which allows the calculation of untried sample configurations.

Knapp, J.A.

1984-01-01T23:59:59.000Z

148

Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams  

DOE Patents [OSTI]

An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.

Hershkowitz, Noah (Madison, WI); Longmier, Benjamin (Madison, WI); Baalrud, Scott (Madison, WI)

2009-03-03T23:59:59.000Z

149

Bioavailability of Fe(III) in Loess Sediments: An Important Source of Electron Acceptors  

SciTech Connect (OSTI)

A quantitative study was conducted to understand if Fe (III) in loess sediments is available for microbial respiration by using a common metal reducing bacterium, Shewanella putrefaciens, CN32. The loess samples were collected from three different sites: St. Louis (Peoria), Missouri, USA; Huanxia (HX) and Yanchang (YCH), Shanxi Province of China. Wet chemical analyses indicated that the total Fe concentration for the three samples was 1.69%, 2.76%, and 3.29%, respectively, of which 0.48%, 0.67%, and 1.27% was Fe(III). All unreduced loess sediments contained iron oxides and phyllosilicates (smectite, illite, chlorite, vermiculite), in addition to common minerals such as quartz, feldspar, plagioclase, calcite, and dolomite. Bioreduction experiments were performed at a loess concentration of 20 mg/mL using lactate as the sole electron donor, Fe(III) in loess as the sole electron acceptor in the presence and absence of anthraquinone-2, 6-disulfonate (AQDS) as an electron shuttle. Experiments were performed in non-growth (bicarbonate buffer) and growth (M1) media with a cell concentration of ~2.8 x 107 and 2.1 x 107 cells/mL, respectively. The unreduced and bioreduced solids were analyzed by X-ray diffraction (XRD), Mössbauer spectroscopy, diffuse reflection spectroscopy (DRS), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods. Despite many similarities among the three loess samples, the extent and rate of Fe (III) reduction varied significantly. For example, in presence of AQDS the extent of reduction in the non-growth experiment was 25% in HX, 34% in Peoria, and 38% in YCH. The extent of reduction in the growth experiment was 72% in HX, 94% in Peoria, and 56% in YCH. The extent of bioreduction was lower in absence of AQDS. Overall, AQDS and the M1 growth medium significantly enhanced the rate and extent of bioreduction. Fe(III) in iron oxides and Fe(III)-containing phyllosilicates was bioreduced. Biogenic illite, siderite, and vivianite formed. The results of this study suggest that Fe (III) in loess sediments represents a potentially important source of electron acceptors to support microbial activity in dry environments.

Bishop, Michael E.; Jaisi, Deb P.; Dong, Hailiang; Kukkadapu, Ravi K.; Ji, Junfeng

2010-08-01T23:59:59.000Z

150

Experiments with biased side electrodes in electron cyclotron resonance ion sources  

E-Print Network [OSTI]

The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses.One route towards a solution consists of attacking the losses in directions (i.e., radial directions) that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six side electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable,...

Drentje, A G; Uchida, T; Rácz, R; Biri, S

2015-01-01T23:59:59.000Z

151

Plasma studies of the permanent magnet electron cyclotron resonance ion source at Peking University  

SciTech Connect (OSTI)

At Peking University (PKU) we have developed several 2.45 GHz Permanent Magnet Electron Cyclotron Resonance ion sources for PKUNIFTY, SFRFQ, Coupled RFQ and SFRFQ, and Dielectric-Wall Accelerator (DWA) projects (respectively, 50 mA of D{sup +}, 10 mA of O{sup +}, 10 mA of He{sup +}, and 50 mA of H{sup +}). In order to improve performance of these ion sources, it is necessary to better understand the principal factors that influence the plasma density and the atomic ion fraction. Theoretical analysis about microwave transmission and cut-off inside the discharge chamber were carried out to study the influence of the discharge chamber diameters. As a consequence, experimental studies on plasma density and ion fraction with different discharge chamber sizes have been carried out. Due to the difficulties in measuring plasma density inside the discharge chamber, the output beam current was measured to reflect the plasma density. Experimental results show that the plasma density increases to the maximum and then decreases significantly as the diameter changed from 64 mm to 30 mm, and the atomic ion fraction has the same tendency. The maximum beam intensity was obtained with the diameter of 35 mm, but the maximum atomic ion fraction with a diameter of 40 mm. The experimental results are basically accordant with the theoretical calculation. Details are presented in this paper.

Ren, H. T.; Peng, S. X., E-mail: sxpeng@pku.edu.cn; Xu, Y.; Zhao, J.; Lu, P. N.; Chen, J.; Zhang, A. L.; Zhang, T.; Guo, Z. Y.; Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

2014-02-15T23:59:59.000Z

152

Lifetime measurement of metastable fluorine atoms using electron cyclotron resonance plasma source  

SciTech Connect (OSTI)

The authors have measured the lifetime of metastable state (3s {sup 4}P{sub 5/2}) of F atoms by resonant laser-induced fluorescence method. For this experiment, a special 2.45 GHz electron cyclotron resonance (ECR) plasma source, which is highly efficient in F radical generation and free from magnetic field leakage in front of the beam-emitting orifice, has been developed. Using the ECR plasma gun, the authors observed a precision fluorescence spectrum related to 3p {sup 4}D{sub 7/2}{sup 0}(F=4){yields}3s {sup 4}P{sub 5/2}(F=3) transition of F radicals, which made it possible to experimentally determine the longitudinal velocity distribution and the angular spread of the F radical beam. Based on these measured beam characteristics, the authors extracted a true decay curve of fluorescence intensity as a function of distance from the source and determined the lifetime of F metastable state (3s {sup 4}P{sub 5/2}) as 7.3{+-}0.5 {mu}s.

Shimizu, Masao; Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi [Yasu Semiconductor Corporation, 686-1 Ichimiyake, Yasu-cho, Yasu-gun, Shiga 520-2632 (Japan); Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2006-11-15T23:59:59.000Z

153

Comparative analysis of neutron sources produced by low-energy electrons and deuterons for driving subcritical assemblies.  

SciTech Connect (OSTI)

A conceptual design of an accelerator driven subcritical assembly has been developed using the existing accelerators at Kharkov Institute of Physics and Technology (KIPT) in Ukraine. Two different external neutron source options were examined for driving the subcritical assembly. Electrons with energies below 200 MeV and deuterons with energies below 100 MeV were considered. Comparative analysis of these two options is presented and discussed. The Comparative analysis of neutron sources produced by low-energy electrons and deuterons show that: (1) An electron accelerator with electron energy in the range of 150 to 200 MeV is preferred for producing neutron source; (2) The uranium target material produces the highest neutron yield per electron; (3) The uranium target with 100 KW electron beam produces 3.3 x 10{sup 14} n/s; (4) The thermal hydraulics analyses of the uranium target operating with the 100 KW electron beam power satisfy the engineering design requirements; and (5) The peak thermal stresses (secondary stress) is less than the yield strength of the uranium target material.

Naberezhnev, D.; Gohar, Y.; Belch, H.; Duo, J.; Bolshinsky, I. (Nuclear Engineering Division); (INL)

2008-04-10T23:59:59.000Z

154

Direct laser acceleration of electrons in free-space  

E-Print Network [OSTI]

Compact laser-driven accelerators are versatile and powerful tools of unarguable relevance on societal grounds for the diverse purposes of science, health, security, and technology because they bring enormous practicality to state-of-the-art achievements of conventional radio-frequency accelerators. Current benchmarking laser-based technologies rely on a medium to assist the light-matter interaction, which impose material limitations or strongly inhomogeneous fields. The advent of few cycle ultra-intense radially polarized lasers has materialized an extensively studied novel accelerator that adopts the simplest form of laser acceleration and is unique in requiring no medium to achieve strong longitudinal energy transfer directly from laser to particle. Here we present the first observation of direct longitudinal laser acceleration of non-relativistic electrons that undergo highly-directional multi-GeV/m accelerating gradients. This demonstration opens a new frontier for direct laser-driven particle accelerati...

Carbajo, Sergio; Wong, Liang Jie; Miller, R J Dwayne; Kärtner, Franz X

2015-01-01T23:59:59.000Z

155

Printed from AccessScience @ McGraw-Hill (www.AccessScience.com). Copyright 2000, 2001, 2002 The McGraw-Hill Companies. All rights reserved. Any use is subject to the  

E-Print Network [OSTI]

at the website. Laser-driven x-ray sources ver since the invention of the microscope, one of the great trends, which can then be used to convert light to short pulses of x- rays. Electron motion in laser fields physics Physics: Lasers Page 1 of 6Laser-driven x-ray sources 3/14/2003http://www

Umstadter, Donald

156

ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE VISIBILITIES  

E-Print Network [OSTI]

ELECTRON FLUX SPECTRAL IMAGING OF SOLAR FLARES THROUGH REGULARIZED ANALYSIS OF HARD X-RAY SOURCE a new method for imaging spectroscopy analysis of hard X-ray emission during solar flares. The method.e., the two-dimensional spatial Fourier transforms of the spectral image) to obtain smoothed (regularized

Piana, Michele

157

Electronic Activation At Oxide Hetero-structure At Elevated Temperatures Source Of Markedly Accelerated Oxygen Reduction Kinetics  

E-Print Network [OSTI]

Electronic Activation At Oxide Hetero-structure At Elevated Temperatures ­ Source Of Markedly a Laboratory for Electrochemical Interfaces, Department of Nuclear Science and Engineering, Massachusetts hand, makes this kind of fuel cell very efficient because of faster transport and electrochemical

Yildiz, Bilge

158

SOURCE?  

Energy Savers [EERE]

Department of Energy (DOE) in partnership with Lawrence Berkeley National Laboratory (LBNL), is an open-source code package designed to be a common, low-cost, standardized tool...

159

Nb3Sn superconducting magnets for electron cyclotron resonance ion sources  

E-Print Network [OSTI]

the design of a N b S n superconducting magnet system for aNbjSn superconducting magnets for electron cyclotron5 C H 1 1 2 3 1 . Nb Sn superconducting magnets for electron

Ferracin, P.

2011-01-01T23:59:59.000Z

160

Noncollisional heating and electron energy distributions in magnetically enhanced inductively coupled and helicon plasma sources  

E-Print Network [OSTI]

region. This enhancement results from noncollisional heating by the axial electric field for electrons­11 The mecha- nisms through which more efficient heating of electrons oc- curs in these systems are not well- teraction mechanism is electron acceleration by the parallel component of the electric field. The heating

Kushner, Mark

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161

Time evolution of endpoint energy of Bremsstrahlung spectra and ion production from an electron cyclotron resonance ion source  

SciTech Connect (OSTI)

Electron cyclotron resonance ion sources (ECRIS) are used to produce high charge state heavy ion beams for the use of nuclear and materials science, for instance. The most powerful ECR ion sources today are superconducting. One of the problems with superconducting ECR ion sources is the use of high radio frequency (RF) power which results in bremsstrahlung radiation adding an extra heat load to the cryostat. In order to understand the electron heating process and timescales in the ECR plasma, time evolution measurement of ECR bremsstrahlung was carried out. In the measurements JYFL 14 GHz ECRIS was operated in a pulsed mode and bremsstrahlung data from several hundred RF pulses was recorded. Time evolution of ion production was also studied and compared to one of the electron heating theories. To analyze the measurement data at C++ program was developed. Endpoint energies of the bremsstrahlung spectra as a function of axial magnetic field strength, pressure and RF power are presented and ion production timescales obtained from the measurements are compared to bremsstrahlung emission timescales and one of the stochastic heating theories.

Tarvainen, Ollie [Los Alamos National Laboratory; Ropponen, Tommi [JYFL; Jones, Peter [JYFL; Kalvas, Taneli [JYFL

2008-01-01T23:59:59.000Z

162

Case studies in the digital fabrication of open-source consumer electronic products  

E-Print Network [OSTI]

This thesis explores the effects of digital fabrication on the design, production, and customization of consumer electronic devices. It does so through a series of three case studies - a radio, a pair of speakers, and a ...

Mellis, David Adley

2011-01-01T23:59:59.000Z

163

Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6  

SciTech Connect (OSTI)

The reduction of hexavalent chromium, Cr(VI), to trivalent chromium, Cr(III), can be an important aspect of remediation processes at Department of Energy (DOE) and other contaminated sites. Cellulomonas species are found at several Cr(VI) contaminated and uncontaminated locations at the DOE site in Hanford, Washington. Members of this genus have demonstrated the ability to effectively reduce Cr(VI) to Cr(III) fermentatively and therefore play a potential role in hexavalent chromium remediation at this site. Batch studies were conducted with Cellulomonas sp. strain ES6 to assess the influence of various carbon sources, iron minerals, and electron shuttling compounds on Cr(VI) reduction. These chemical species are likely to be present in these terrestrial environments during in situ bioremediation. Results indicated that there were a number of interactions between these compounds that influenced Cr(VI) reduction rates. The type of carbon source as well as the type of electron shuttle present influenced Cr(VI) reduction rates. When an electron shuttle, such as anthraquinone-2,6-disulfonate (AQDS), was present in the system, reduction rates increased significantly. Biologically reduced AQDS (AHDS) reduced Cr(VI) almost instantaneously. The presence of iron minerals and their concentrations did not significantly influence Cr(VI) reduction rates. However, strain ES6 or AQDS could directly reduce surface-associated Fe(III) to Fe(II) which was capable of reducing Cr(VI) at a near instantaneous rate. These results suggest the rate limiting step in these systems is the transfer of electrons from strain ES6 to the intermediate or terminal electron acceptor whether that is Cr(VI), Fe(III), or AQDS.

Erin K. Field; Robin Gerlach; Sridhar Viamajala; Laura K. Jennings; Alfred B. Cunningham; Brent M. Peyton; William A. Apel

2011-09-01T23:59:59.000Z

164

Scaling relations and parameters for 1 Angstrom FEL. [Free Electron Laser  

SciTech Connect (OSTI)

The Free Electron Laser (FEL) holds great promise as a tunable source of coherent radiation. At the present, the shortest wavelength achieved by an FEL is 2500 {Angstrom}. However, as recent progress in the development of laser driven photocathode electron guns has provided electron beams with lower and lower emittance and higher and higher current, it has become clear that FEL's with much shorter wavelength can be achieved. An FEL operating below 1000 {Angstrom} will yield important advances in fields such as photochemistry, atomic and molecular physics. An FEL with wavelength of 30 {Angstrom} will bring new era to the development of holography of living cells. And, if an FEL with 1 {Angstrom} wavelength can be developed, its impact on solid physics, molecular biology, and many other fields can hardly be exaggerated. We first describe our electron distribution model: a waterbag transverse phase space distribution and a Gaussian energy distribution. This model is widely used in simulations, and is rather close to reality. Then we describe the dispersion relation derived from the Vlasov-Maxwell equations, and its solution, expressed in scaled form. We compare the variational approximation with several simulation codes. Then we compare with exact results which we have derived for a parallel electron beam with finite beam size and energy spread. We explain the scaling relations, and give examples to show how system parameters scale when the FEL wavelength is reduced. Then, applying these scaling relations, we derive a list of preliminary system parameters for a 1 {Angstrom} FEL. As an example, we apply our analytical calculation to optimize one set of parameters derived from the scaling relations. Finally, as a conclusion we discuss the implication of the list of parameters for a 1{Angstrom} FEL. 20 refs., 4 figs.

Yu, L.H.

1990-01-01T23:59:59.000Z

165

Study of an HHG-Seeded Free-Electron Laser for the LBNL Next Generation Light Source  

SciTech Connect (OSTI)

The Next Generation Light Source (NGLS) is a high repetition rate free-electron laser facility proposed by Lawrence Berkeley National Laboratory (LBNL). The proposed facility will provide multiple FEL lines with varying spectral characteristics to satisfy a broad soft X-ray physics programme. At this stage of the project a number of FEL technologies and concepts are being investigated for possible implementation on the facility. In this report we consider a free-electron laser seeded by a Higher Harmonic Generation (HHG) source in which a high power (and consequently relatively low repetition rate) laser pulse is injected into a chamber of inert gas. Through a process of ionisation and recombination coherent higher harmonics of the laser are emitted from the gas and can be injected into an FEL system as a seed field. Further harmonic upconversion can be done within the FEL system to enable temporally coherent FEL output at wavelengths much shorter than, and pulse energies orders of magnitude higher than, the HHG source emission. The harmonic conversion within the FEL works in the following way. The seed field induces an energy modulation within the electron bunch at the start of the modulator. This energy modulation grows within the modulator due to the FEL interaction and starts to convert into a density modulation, or bunching, at the seed wavelength. However, this bunching also has components at higher harmonics which retain the longitudinal coherence of the initial seed. The beam passes through a magnetic chicane, which shears the longitudinal phase space to maximise the bunching at the required harmonic, then a further undulator which is tuned to this harmonic. If this second undulator is short it acts as a further modulator, and because the beam is pre-bunched at the modulator resonance there is a strong coherent burst of radiation which acts to modulate the electron beam energy in much the same way the input laser seed field acted in the first modulator. This second modulator is followed by a second bunching chicane and then a final long radiator tuned to a yet higher harmonic of the laser seed - the final output wavelength. Alternatively, the second undulator can be the radiator itself, in which case only one harmonic conversion from seed wavelength to final output is necessary. We initially consider the case of a 400kW peak power HHG seed source at wavelength 12nm (currently considered the cutoff wavelength for sufficient seed power to dominate shot noise in the electron beam) which is converted in either one or two stages or harmonic conversion to FEL emission at 1nm. We then consider the implications of a factor of ten reduction in seed power to 40kW.

Thompson, Neil

2010-10-20T23:59:59.000Z

166

Variable Gap Undulator for 1.5-48 Kev Free Electron Laser at Linac Coherent Light Source  

SciTech Connect (OSTI)

We study the feasibility of generating femtosecond duration Free-Electron Laser with a variable photon energy from 1.5 to 48 keV, using an electron bunch with the same characteristics of the LINAC Coherent Light Source (LCLS) bunch, and a planar undulator with additional focusing. We assume that the electron bunch energy can be changed, and the undulator has a variable gap, allowing a variable undulator parameter. It is assumed to be operated in an ultra-low charge and ultra-short pulse regime. We study the feasibility of a tunable, short pulse, X-ray FEL with photon energy from 1.5 to 48 keV, using an electron beam like the one in the LCLS and a 2:5 cm period, variable gap, planar undulator. The beam energy changes from 4.6 to 13.8 GeV, the electorn charge is kept at 10 pC, and the undulator parameter varies from 1 to 3. The undulator length needed to saturate the 48 keV FEL is about 55 m, with a peak power around 5 GW. At longer wavelength the saturation length is as short as 15 m, and the peak power around 20 GW. The results from the analytical models and the GENESIS simulations show that the system is feasible. The large wavelength range, full tunability and short, few femtosecond pulses, together with the large peak power, would provide a powerful research tool.

Pellegrini, C.; /UCLA; Wu, J.; /SLAC; ,

2011-08-17T23:59:59.000Z

167

Design of a compact electron cyclotron resonance ion source for medium charge state light ions  

SciTech Connect (OSTI)

At the Australian Nuclear Science and Technology Organization we are developing a new isotope ratio mass spectrometer based on the measurement of multiple charge state ions. We have carried out a review of our existing ECR ion source and identified a number of design flaws. For the new instrument, we are producing a new ECR source and have refined the design, in particular by using 3D simulations to improve the magnetic confinement field and by a combination of simulations and experiments to improve the design of the microwave coupling.

Button, D.; Hotchkis, M. A. C. [Australian Nuclear Science and Technology Organization, Sydney, NSW 2234 (Australia); Milford, G. N. [University of New South Wales, Canberra, ACT 2600 (Australia)

2012-02-15T23:59:59.000Z

168

No Universality for Electron's Power-Law Index (p) in Gamma-Ray Bursts and Other Relativistic Sources  

E-Print Network [OSTI]

The Gamma-Ray Burst (GRB) prompt emission is believed to be from highly relativistic electrons accelerated in relativistic shocks. From the GRB high-energy power-law spectral indices $\\beta$ observed by the Burst and Transient Source Experiment (BATSE) Large Area Detectors (LAD), we determine the spectral index, $p$, of the electrons' energy distribution. Both the theoretical calculations and numerical simulations of the particle acceleration in relativistic shocks show that $p$ has a universal value $\\approx 2.2-2.3$. We show that the observed distribution of $p$ during GRBs is not consistent with a $\\delta$-function distribution or an universal $p$ value, with the width of the distribution $\\ge$ 0.54. The distributions of $p$ during X-ray afterglows are also investigated and found to be inconsistent with a $\\delta$-function distribution. The $p$-distributions in blazars and pulsar wind nebulae are also broad, inconsistent with a $\\delta$-function distribution.

R. -F. Shen; P. Kumar; E. L. Robinson

2006-06-27T23:59:59.000Z

169

Dark matter conversion as a source of boost factor for explaining the cosmic ray positron and electron excesses  

E-Print Network [OSTI]

In interacting multi-component dark matter (DM) models, if the DM components are nearly degenerate in mass and the interactions between them are strong enough, the relatively heavy DM components can be converted into lighter ones at late time after the thermal decoupling. Consequently, the relic density of the lightest DM component can be considerably enhanced at late time. This may contribute to an alternative source of boost factor required to explain the positron and electron excesses reported by the recent DM indirect search experiments such as PAMELA, Fermi-LAT and HESS etc..

Ze-Peng Liu; Yue-Liang Wu; Yu-Feng Zhou

2011-12-17T23:59:59.000Z

170

Tunable Radiation Source by Coupling Laser-Plasma-Generated Electrons to a Periodic Structure  

SciTech Connect (OSTI)

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Jin, Z. [Photon Pioneers Center, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Chen, Z. L.; Kon, A.; Nakatsutsumi, M. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Zhuo, H. B. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); School of Science, National University of Defense Technology, Changsha 410073 (China); Wang, H. B.; Zhang, B. H.; Gu, Y. Q.; Wu, Y. C.; Zhu, B.; Wang, L. [National Key Laboratory of Laser Fusion, CAEP, Mianyang 621900 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany); Sheng, Z. M. [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Kodama, R. [Photon Pioneers Center, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871 (Japan); Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565-0871 (Japan)

2011-12-23T23:59:59.000Z

171

Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6  

SciTech Connect (OSTI)

Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy's Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity.

Dr Robin Gerlach; Erin K. Field; Sridhar Viamajala; Brent M. Peyton; William A. Apel; Al B. Cunningham

2011-09-01T23:59:59.000Z

172

Enhanced field emission from cerium hexaboride coated multiwalled carbon nanotube composite films: A potential material for next generation electron sources  

SciTech Connect (OSTI)

Intensified field emission (FE) current from temporally stable cerium hexaboride (CeB{sub 6}) coated carbon nanotubes (CNTs) on Si substrate is reported aiming to propose the new composite material as a potential candidate for future generation electron sources. The film was synthesized by a combination of chemical and physical deposition processes. A remarkable increase in maximum current density, field enhancement factor, and a reduction in turn-on field and threshold field with comparable temporal current stability are observed in CeB{sub 6}-coated CNT film when compared to pristine CeB{sub 6} film. The elemental composition and surface morphology of the films, as examined by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray measurements, show decoration of CeB{sub 6} nanoparticles on top and walls of CNTs. Chemical functionalization of CNTs by the incorporation of CeB{sub 6} nanoparticles is evident by a remarkable increase in intensity of the 2D band in Raman spectrum of coated films as compared to pristine CeB{sub 6} films. The enhanced FE properties of the CeB{sub 6} coated CNT films are correlated to the microstructure of the films.

Patra, Rajkumar; Ghosh, S., E-mail: santanu1@physics.iitd.ac.in [Nanostech Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi-16 (India); Sheremet, E.; Rodriguez, R. D.; Lehmann, D.; Gordan, O. D.; Zahn, D. R. T. [Semiconductor Physics, Technische Universität Chemnitz, 09126 Chemnitz (Germany); Jha, M.; Ganguli, A. K. [Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-16 (India); Schmidt, H. [Material Systems for Nanoelectronics, Technische Universität Chemnitz, 09126 Chemnitz (Germany); Schulze, S. [Solid Surfaces Analysis, Technische Universität Chemnitz, 09126 Chemnitz (Germany); Schmidt, O. G. [Material Systems for Nanoelectronics, Technische Universität Chemnitz, 09126 Chemnitz (Germany); Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden (Germany)

2014-03-07T23:59:59.000Z

173

Electron cyclotron resonant multicusp magnetic field microwave plasma source for electric propulsion  

SciTech Connect (OSTI)

The development of electrodeless microwave ion and plasma sources has been a recent, very active research project at Michigan State University. The results are efficient, compact microwave discharge configurations that operate at low pressures (0.5 mtorr to 100 mtorr) and efficiently produce low energy ions and free radicals and broad ion beams for oxidation, deposition, and etching experiments. The microwave discharge technology developed for these applications may be useful for application in electric propulsion. This paper reviews this microwave applicator technology and indicates how it may be extended to higher power levels and applied to electric propulsion systems. 12 references.

Dahimene, M.; Mahoney, L.; Asmussen, J.

1987-05-01T23:59:59.000Z

174

Development of a high-temperature oven for the 28 GHz electron cyclotron resonance ion source  

SciTech Connect (OSTI)

We have been developing the 28 GHz ECR ion source in order to accelerate high-intensity uranium beams at the RIKEN RI-beam Factory. Although we have generated U{sup 35+} beams by the sputtering method thus far, we began developing a high-temperature oven with the aim of increasing and stabilizing the beams. Because the oven method uses UO{sub 2}, a crucible must be heated to a temperature higher than 2000?°C to supply an appropriate amount of UO{sub 2} vapor to the ECR plasma. Our high-temperature oven uses a tungsten crucible joule-heated with DC current of approximately 450 A. Its inside dimensions are ?11 mm × 13.5 mm. Since the crucible is placed in a magnetic field of approximately 3 T, it is subject to a magnetic force of approximately 40 N. Therefore, we used ANSYS to carefully design the crucible, which was manufactured by machining a tungsten rod. We could raise the oven up to 1900?°C in the first off-line test. Subsequently, UO{sub 2} was loaded into the crucible, and the oven was installed in the 28 GHz ECR ion source and was tested. As a result, a U{sup 35+} beam current of 150 ?A was extracted successfully at a RF power of approximately 3 kW.

Ohnishi, J., E-mail: ohnishi@riken.jp; Higurashi, Y.; Kidera, M.; Ozeki, K.; Nakagawa, T. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)] [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

2014-02-15T23:59:59.000Z

175

Design and characterization of 2.45 GHz electron cyclotron resonance plasma source with magnetron magnetic field configuration for high flux of hyperthermal neutral beam  

SciTech Connect (OSTI)

A 2.45 GHz electron cyclotron resonance (ECR) source with a magnetron magnetic field configuration was developed to meet the demand of a hyperthermal neutral beam (HNB) flux on a substrate of more than 1x10{sup 15} cm{sup -2} s{sup -1} for industrial applications. The parameters of the operating pressure, ion density, electron temperature, and distance between the neutralization plate and the substrate for the HNB source are specified in a theoretical analysis. The electron temperature and the ion density are measured to characterize the ECR HNB source using a Langmuir probe and optical emission spectroscopy. The parameters of the ECR HNB source are in good agreement with the theoretically specified parameters.

Kim, Seong Bong [Department of Physics, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of); Convergence Plasma Research Center, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Kim, Dae Chul; Yoo, Suk Jae [Convergence Plasma Research Center, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Namkung, Won; Cho, Moohyun [Department of Physics, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of)

2010-08-15T23:59:59.000Z

176

Conceptual design of first toroidal electron cyclotron resonance ion source and modeling of ion extraction from it  

E-Print Network [OSTI]

Electron Cyclotron Resonance Ion Sources (ECRIS) progressed to higher and higher ion currents and charge states by adopting stronger magnetic fields (beneficial for confinement) and proportionally higher ECR frequencies. Further improvements would require the attainment of "triple products" of density, temperature and confinement time comparable with major fusion experiments. For this, we propose a new, toroidal rather than linear, ECRIS geometry, which would at the same time improve confinement and make better use of the magnetic field. Ion extraction is more complicated than from a linear device, but feasible, as our modelling suggests: single-particle tracings showed successful extraction by at least two techniques, making use respectively of a magnetic extractor and of ExB drifts. Additional techniques are briefly discussed.

Caliri, C; Volpe, F A

2015-01-01T23:59:59.000Z

177

Nonlinear Pulse Propagation and Phase Velocity of Laser-Driven Plasma Waves C. B. Schroeder, C. Benedetti, E. Esarey, and W. P. Leemans  

E-Print Network [OSTI]

of high-quality GeV electron beams in centimeter-scale plasmas [2], the dynamics of the acceler- ated- ing length (distance for a relativistic particle to move out of an accelerating phase) and, hence=cm2 , or a0 * 1, to drive large ampli- tude plasma waves for particle acceleration. In the nonlinear

Geddes, Cameron Guy Robinson

178

X-ray spectroscopy of warm and hot electron components in the CAPRICE source plasma at EIS testbench at GSI  

SciTech Connect (OSTI)

An experimental campaign aiming to detect X radiation emitted by the plasma of the CAPRICE source – operating at GSI, Darmstadt – has been carried out. Two different detectors (a SDD – Silicon Drift Detector and a HpGe – hyper-pure Germanium detector) have been used to characterize the warm (2–30 keV) and hot (30–500 keV) electrons in the plasma, collecting the emission intensity and the energy spectra for different pumping wave frequencies and then correlating them with the CSD of the extracted beam measured by means of a bending magnet. A plasma emissivity model has been used to extract the plasma density along the cone of sight of the SDD and HpGe detectors, which have been placed beyond specific collimators developed on purpose. Results show that the tuning of the pumping frequency considerably modifies the plasma density especially in the warm electron population domain, which is the component responsible for ionization processes: a strong variation of the plasma density near axis region has been detected. Potential correlations with the charge state distribution in the plasma are explored.

Mascali, D., E-mail: davidmascali@lns.infn.it; Celona, L.; Castro, G.; Torrisi, G.; Neri, L.; Gammino, S.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy)] [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Maimone, F.; Maeder, J.; Tinschert, K.; Spaedtke, K. P.; Rossbach, J.; Lang, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany)] [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Romano, F. P. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy) [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); Musumarra, A.; Altana, C.; Caliri, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy) [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, – Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, via S. Sofia 64, 95123 Catania (Italy)

2014-02-15T23:59:59.000Z

179

Temporal synchronization of GHz repetition rate electron and laser pulses for the optimization of a compact inverse-Compton scattering x-ray source  

E-Print Network [OSTI]

The operation of an inverse-Compton scattering source of x-rays or gamma-rays requires the precision alignment and synchronization of highly focused electron bunches and laser pulses at the collision point. The arrival times of electron and laser pulses must be synchronized with picosecond precision. We have developed an RF synchronization technique that reduces the initial timing uncertainty from 350 ps to less than 2 ps, greatly reducing the parameter space to be optimized while commissioning the x-ray source. We describe the technique and present measurements of its performance.

Hadmack, Michael R; Madey, John M J; Kowalczyk, Jeremy M D

2014-01-01T23:59:59.000Z

180

Numerical study of atomic production rate in hydrogen negative ion sources with the effect of non-equilibrium electron energy distribution function  

SciTech Connect (OSTI)

Spatial non-uniformity of the dissociative hydrogen atom (H{sup 0}) production has been investigated in a large negative ion source (JAEA 10 A source) with the electron energy distribution function (EEDF) obtained by a Monte-Carlo simulation code for electron transport in 3D3V (three dimensional real and velocity) space. It has been shown that the H{sup 0} production rate becomes larger in the upper region (one side in the longitudinal direction) of the source chamber. This spatial non-uniformity of the H{sup 0} production profile is mainly explained by the non-equilibrium features of the EEDF in the upper region, i.e., the EEDF consists of thermal electron component with kinetic energy ? < 25 eV and fast electron component with energy ? > 25 eV in the upper region, while the EEDF mainly consists of only thermal electrons in the bottom region. These characteristics for the EEDF and the energy dependence of cross-sections for dissociation and dissociative ionization processes lead to the non-uniform profile of the H{sup 0} production. The above numerical results of the spatial H{sup 0} non-uniformity are validated and confirmed by comparisons with those by spectroscopic measurement. It has been clarified that the non-equilibrium (fast electron) component of the EEDF has a large contribution to the non-uniformity of the H{sup 0} production rate.

Shibata, T.; Hatayama, A. [Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan)] [Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Kashiwagi, M.; Inoue, T.; Hanada, M. [Japan Atomic Energy Agency, 801-1 Mukouyama, Naka 311-0193 (Japan)] [Japan Atomic Energy Agency, 801-1 Mukouyama, Naka 311-0193 (Japan)

2013-10-14T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

E-Print Network 3.0 - accelerated finite difference Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doi:10.10880953-4075389020 Summary: sources for future laser-driven particle accelerators. Several different laser-driven acceleration... 's theory of special relativity on...

182

Development of a microwave ion and plasma source immersed in a multicusp electron-cyclotron-resonant magnetic field  

SciTech Connect (OSTI)

Experimental development and test of an electrodeless microwave (2.45 GHz)-generated plasma and ion source in a discharge pressure range of 6 x 10 /sup -4/-5 x 10/sup -1/ Torr and relatively low power (80-350 W CW) are presented. Also presented is a semi-empirical model applicable to low-pressure microwave discharges with no static magnetic field. Initial experiments studied the properties of variable diffusion length (0.43-1.22 cm) disk-shaped discharges generated and maintained in a cylindrical microwave resonant-cavity applicator for argon and oxygen gases without a static magnetic field. These discharges were characterized by measuring plasma densities and electron temperatures using a Langmuir double probe for different experimental conditions. The measured plasma densities and electron temperatures ranged for 8 x 10/sup 10/ to 5 x 10 /sup 11/ cm/sup -3/ and 2 x 10/sup 4/ to 8 x 10/sup 4/ /sup 0/K, respectively. The ion temperature was less than 500 /sup 0/K. Ion beams were extracted from these discharges using single and double grids. Argon ion-beam currents densities were measured to be 3.0 mA/cm/sup 2/ for the single grid and 5.8 mA/cm/sup 2/ for the double grids with a maximum extraction voltage of 1.7 kV. This applicator was then retrofitted with magnets to study the effect of a multicusp static magnetic field. Using this concept, a new cylindrical microwave applicator was designed and tested.

Dahimene, M.

1987-01-01T23:59:59.000Z

183

Note: A novel normalization scheme for laser-based plasma x-ray sources  

SciTech Connect (OSTI)

A kHz repetition rate laser pump-X-ray probe system for ultrafast X-ray diffraction is set up based on a laser-driven plasma X-ray source. A simple and reliable normalization approach has been developed to minimize the impact of large X-ray pulse intensity fluctuation on data quality. It utilizes one single X-ray area detector to record both sample and reference signals simultaneously. Performance of this novel normalization method is demonstrated in reflectivity oscillation measurement of a superlattice sample at sub-ps resolution.

Zhang, B. B.; Sun, D. R.; Tao, Y., E-mail: taoy@ihep.ac.cn [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Sun, S. S. [Institute of Physics, Chinese Academy of Sciences, Beijing 100090 (China)

2014-09-15T23:59:59.000Z

184

Correspondence: Email: shinn@jlab.org; Telephone: 757 269 7565; FAX: 757 269 5519 High Average Power Free-Electron Lasers -A New Laser Source for  

E-Print Network [OSTI]

Power Free-Electron Lasers - A New Laser Source for Materials Processing Michelle D. Shinn Thomas). In general, the processing consists of material removal steps such as drilling, cutting, as well as joining technology provides a scaleable path to laser outputs above 50 kW, rendering these applications economically

185

2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe  

SciTech Connect (OSTI)

A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

Chen, Y. H.; Yang, X. Y.; Lin, C., E-mail: linchen0812@pku.edu.cn, E-mail: cjxiao@pku.edu.cn; Wang, X. G.; Xiao, C. J., E-mail: linchen0812@pku.edu.cn, E-mail: cjxiao@pku.edu.cn [State Key Lab of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Wang, L. [Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190 (China); Xu, M. [Center for Fusion Science of Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041 (China)

2014-11-15T23:59:59.000Z

186

Optically pulsed electron accelerator  

DOE Patents [OSTI]

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

187

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

of high- gradient, laser plasma particle accelerators.accelerators that use laser-driven plasma waves. Theseleft) showing the laser (red), plasma wake density (purple-

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

188

High density laser-driven target  

DOE Patents [OSTI]

A high density target for implosion by laser energy composed of a central quantity of fuel surrounded by a high-Z pusher shell with a low-Z ablator-pusher shell spaced therefrom forming a region filled with low-density material.

Lindl, John D. (San Ramon, CA)

1981-01-01T23:59:59.000Z

189

Laser Driven Dynamic Loading of Condensed Matter  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs space CombinedValuesRevolutionizing theLaser

190

890 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 4, JULY 2006 A Self-Adjusting Sinusoidal Power Source  

E-Print Network [OSTI]

Mordechai Peretz Abstract--A new self-adjusting current-fed push­pull parallel inverter (SA the amplitude, waveform and efficiency of the power driver. The current-fed push­pull resonant inverter (CFPPRI890 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 4, JULY 2006 A Self-Adjusting Sinusoidal

191

Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source  

SciTech Connect (OSTI)

An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.

Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

2014-02-14T23:59:59.000Z

192

Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source  

SciTech Connect (OSTI)

We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen K? x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-?m scale three-dimensional fine structures were resolved.

Ohsuka, Shinji, E-mail: ohsuka@crl.hpk.co.jp [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); The Graduate School for the Creation of New Photonics Industries, 1955-1 Kurematsu-cho, Nishi-ku, Hamamatsu-City, 431-1202 (Japan); Ohba, Akira; Onoda, Shinobu; Nakamoto, Katsuhiro [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); Nakano, Tomoyasu [Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu-City, 434-8601 (Japan); Ray-Focus Co. Ltd., 6009 Shinpara, Hamakita-ku, Hamamatsu-City, 434-0003 (Japan); Miyoshi, Motosuke; Soda, Keita; Hamakubo, Takao [Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

2014-09-15T23:59:59.000Z

193

194 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 56, NO. 1, JANUARY 2009 PWM Method to Eliminate Power Sources in a  

E-Print Network [OSTI]

to Eliminate Power Sources in a Nonredundant 27-Level Inverter for Machine Drive Applications Mauricio Rotella-stage 27-level inverter using "H" converters is analyzed for medium- and high-power machine drive was implemented using DSP controllers, which give flexibility to the system. Index Terms--Drives, multilevel

Catholic University of Chile (Universidad Católica de Chile)

194

IEEE ELECTRON DEVICE LETTERS, VOL. 25, NO. 8, AUGUST 2004 565 N-Type Schottky Barrier Source/Drain MOSFET  

E-Print Network [OSTI]

-aligned rare earth metal-(Erbium, Terbium, Dys- prosium) silicided Schottky junctions. Index Terms/Drain MOSFET Using Ytterbium Silicide Shiyang Zhu, Member, IEEE, Jingde Chen, M.-F. Li, Senior Member, IEEE, S--Ytterbium silicide, for the first time, was used to form the Schottky barrier source/drain (S/D) of N-channel MOSFETs

Fu, Li Ming

195

Waveguide slot-excited long racetrack electron cyclotron resonance plasma source for roll-to-roll (scanning) processing  

SciTech Connect (OSTI)

We present a SLot-excited ANtenna (SLAN) long racetrack ECR plasma source that is utilized for roll-to-roll plasma processing such as thin film encapsulation of large-area OLED (organic light emitting diode) panel or modification of fabric surfaces. This source is designed to be long, and to operate under high density uniform plasma with sub-milli-torr pressures. The above features are accomplished by a slot-excited long racetrack resonator with a toroidal geometry of magnetic field ECR configuration, and reinforced microwave electric distributions along the central region of plasma chamber. Also, a new feature has been added to the source. This is to employ a tail plunger, which allows the microwave electric field and the uniformity of the plasma profile to be easily adjustable. We have successfully generated Ar plasmas operating with the microwave power of 0.5–3 kW in the pressure range of 0.2–10 mTorr. The plasma is uniform (<10%) in the direction of the straight track and has a Gaussian profile in the roll-to-roll (scanning) direction. In addition, it is shown that the tail plunger could adjust the plasma profile in order to obtain plasma uniformity. Furthermore, based on the results, we suggest a newly designed up-scaled racetrack-SLAN source.

You, H.-J. [National Fusion Research Institute, Daejeon (Korea, Republic of)] [National Fusion Research Institute, Daejeon (Korea, Republic of)

2013-07-15T23:59:59.000Z

196

A Beat Frequency RF Modulator for Generation of Low Repetition Rate Electron Microbunches for the CEBAF Polarized Source  

SciTech Connect (OSTI)

Fiber-based drive lasers now produce all of the spin-polarized electron beams at CEBAF/Jefferson Lab. The flexibility of these drive lasers, combined with the existing three-beam CEBAF photoinjector Chopper, provides a means to implement a beat frequency technique to produce long time intervals between individual electron microbunches (tens of nanoseconds) by merely varying the nominal 499 MHz drive laser frequency by < 20%. This submission describes the RF Laser modulator that uses a divider and heterodyne scheme to maintain coherence with the accelerator Master Oscillator (MO), while providing delay resolution in increments of 2ns. Some possible uses for such a beam are discussed as well as intended future development.

John Musson; Reza Kazimi; Benard Poelker; Joseph Grames; John Hansknecht

2007-06-25T23:59:59.000Z

197

A laser-induced repetitive fast neutron source applied for gold activation analysis  

SciTech Connect (OSTI)

A laser-induced repetitively operated fast neutron source was developed for applications in laser-driven nuclear physics research. The developed neutron source, which has a neutron yield of approximately 4 Multiplication-Sign 10{sup 5} n/pulse and can be operated up to a pulse repetition rate of 10 Hz, was applied for a gold activation analysis. Relatively strong delayed gamma spectra of the activated gold were measured at 333 keV and 355 keV, and proved the possibility of the neutron source for activation analyses. In addition, the nuclear reactions responsible for the measured gamma spectra of gold were elucidated by the 14 MeV fast neutrons resulting from the D(t,n)He{sup 4} nuclear reaction, for which the required tritium originated from the primary fusion reaction, D(d,p)T{sup 3}.

Lee, Sungman; Park, Sangsoon; Lee, Kitae; Cha, Hyungki [Quantum Optics Division, Korea Atomic Energy Research Institute, Daejeon 305-600 (Korea, Republic of)

2012-12-15T23:59:59.000Z

198

Design of a compact, permanent magnet electron cyclotron resonance ion source for proton and H{sub 2}{sup +} beam production  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source was developed at China Institute of Atomic Energy (CIAE) for proton beam production of over 60 mA [B.-Q. Cui, Y.-W. Bao, L.-Q. Li, W.-S. Jiang, and R.-W. Wang, Proceedings of the High Current Electron Cyclotron Resonance (ECR) Ion Source for Proton Accelerator, APAC-2001, 2001 (unpublished)]. For various proton beam applications, another 2.45 GHz microwave ion source with a compact structure is designed and will be built at CIAE as well for high current proton beam production. It is also considered to be used for the test of H{sub 2}{sup +} beam, which could be injected into the central region model cyclotron at CIAE, and accelerated to 5 MeV before extraction by stripping. The required ECR magnetic field is supplied by all the permanent magnets rather than electrical solenoids and six poles. The magnetic field distribution provided by this permanent magnets configuration is a large and uniformly volume of ECR zone, with central magnetic field of a magnitude of {approx}875 Gs[T. Taylor and J. S. C. Wills, Nucl. Instrum. Methods Phys. Res. A 309, 37 (1991)]. The field adjustment at the extraction end can be implemented by moving the position of the magnet blocks. The results of plasma, coupling with 2.45 GHz microwave in the ECR zone inside the ion source are simulated by particle-in-cell code to optimize the density by adjusting the magnetic field distribution. The design configuration of the ion source will be summarized in the paper.

Jia Xianlu; Zhang Tianjue; Wang Chuan; Zheng Xia; Yin Zhiguo; Zhong Junqing; Wu Longcheng; Qin Jiuchang [China Institute of Atomic Energy, P.O. Box 275(3), Beijing 102413 (China); Luo Shan [The 6th Department, Communication Command Academy, Wuhan 430010 (China)

2010-02-15T23:59:59.000Z

199

High-resolution total-cross-section measurements for electron scattering from Ar, Kr, and Xe employing a threshold-photoelectron source  

SciTech Connect (OSTI)

Absolute total cross sections for electron scattering from Ar and Xe at electron energies ranging from 7 meV to 20 eV were obtained with the experimental technique employing the threshold-photoelectron source. The measured total cross sections are in good agreement with those obtained by other groups down to 100 meV, above which several experimental works have been reported. Scattering lengths for electron scattering from Ar, Kr, and Xe were determined from the present total cross sections and our recent results for Kr using the modified effective range theory. The values of the scattering length obtained in the present analysis differ from the values determined from the previous swarm experiments and beam experiments. The resonant structures in the total cross sections due to Feshbach resonances of Ar, Kr, and Xe with an improved energy resolution were also measured. Analyses of the resonant structure were carried out based on the spin-dependent resonant scattering theory in order to determine the values of the natural width of Feshbach resonances of Ar, Kr, and Xe precisely.

Kurokawa, M.; Kitajima, M.; Toyoshima, K.; Kishino, T.; Odagiri, T. [Department of Chemistry, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Kato, H.; Hoshino, M.; Tanaka, H. [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Ito, K. [Photon Factory, Institute of Materials Structure Science, Tsukuba 305-0801 (Japan)

2011-12-15T23:59:59.000Z

200

From Clark Lake to Chandra: Closing in on the Low End of the Relativistic Electron Spectra in Extragalactic Sources  

E-Print Network [OSTI]

The limited angular resolutions and sensitivities historically available below 300 MHz have made it difficult to define the low end of the electron energy distribution, N(gamma). We extrapolate down from the well observed segments of radio spectra with almost complete ignorance of what N(gamma) is actually doing. We do not know if there is a low energy cutoff or if there are other deviations from extrapolated power laws. The result is that we really do not have a good estimate of the total energy density and pressure of the relativistic plasmas we study. The situation is even worse for Inverse Compton (IC) X-ray emission, several flavors of which rely on electrons of Lorentz factors, gamma, of 1000, 300, or in some cases of order 50. If our assumed extrapolations are wrong, some IC emission models may have to be abandoned. We present several examples and demonstrate that the Long Wave Array (LWA) should have sufficient sensitivity and resolution to obtain meaningful constraints on N(gamma) at low energies.

D. E. Harris

2004-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source  

SciTech Connect (OSTI)

Purpose: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. Methods: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (D{sub w,m}) and dose to medium (D{sub m,m}), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. Results: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D{sub 90} to PTV was reduced by between ?4% and ?40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%–15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. Conclusions: TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources.

White, Shane A.; Landry, Guillaume; Reniers, Brigitte, E-mail: brigitte.reniers@maastro.nl [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN (Netherlands); Fonseca, Gabriel Paiva [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo CP 11049, 05422-970 (Brazil); Holt, Randy; Rusch, Thomas [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States)] [Xoft, A Subsidiary of iCAD, Sunnyvale, California 94085-4115 (United States); Beaulieu, Luc [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada)] [Centre Hospitalier Universitaire de Québec Université Laval, Radio-Oncologie et Centre de Recherche en Cancérologie de l’Université Laval, Québec, Québec G1R 2J6 Canada (Canada); Verhaegen, Frank [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)] [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, The Netherlands and Department of Oncology, McGill University, Montreal, Quebec H3G 1A4 (Canada)

2014-06-15T23:59:59.000Z

202

Radiation source  

DOE Patents [OSTI]

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

203

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source  

SciTech Connect (OSTI)

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously. We optimize the beam current I{sub FC} by the mobile plate tuner. The I{sub FC} is affected by the position of the mobile plate tuner in the chamber as like a circular cavity resonator. We aim to clarify the relation between the I{sub FC} and the ion saturation current in the ECRIS against the position of the mobile plate tuner. We obtained the result that the variation of the plasma density contributes largely to the variation of the I{sub FC} when we change the position of the mobile plate tuner.

Kurisu, Yosuke; Kiriyama, Ryutaro; Takenaka, Tomoya; Nozaki, Dai; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2012-02-15T23:59:59.000Z

204

Final report for the NSF/DOE partnership in basic plasma science grant DE-FG02-06ER54906 '?Laser-driven collisionless shocks in the Large Plasma Device'?  

SciTech Connect (OSTI)

We have performed several thousand high-energy laser shots in the LAPD to investigate the dynamics of an exploding laser-produced plasma in a large ambient magneto-plasma. Debris-ions expanding at super-Alfvenic velocity (up to MA=1.5) expel the ambient magnetic field, creating a large (> 20 cm) diamagnetic cavity. We observed field compressions of up to B/B{sub 0} = 1.5 at the edge of the bubble, consistent with the MHD jump conditions, as well as localized electron heating at the edge of the bubble. Two-dimensional hybrid simulations reproduce these measurements well and show that the majority of the ambient ions are energized by the magnetic piston to super-Alfvenic speeds and swept outside the bubble volume. Nonlinear shear-Alfven waves ({delta}B/B{sub 0} > 25%) are radiated from the cavity with a coupling efficiency of 70% from magnetic energy in the bubble to the wave. While the data is consistent with a weak magneto-sonic shock, the experiments were severely limited by the low ambient plasma densities (10{sup 12} cm{sup -3}). 2D hybrid simulations indicate that future experiments with the new LAPD plasma source and densities in excess of 10{sup 13} cm{sup -3} will drive full-blown collisionless shocks with MA>10 over several c/wpi and shocked Larmor radii. In a separate experiment at the LANL Trident laser facility we have performed a proof-of-principle experiment at higher densities to demonstrate key elements of collisionless shocks in laser-produced magnetized plasmas with important implications to NIF. Simultaneously we have upgraded the UCLA glass-laser system by adding two large amplitude disk amplifiers from the NOVA laser and boost the on-target energy from 30 J to up to 1 kJ, making this one of the world’s largest university-scale laser systems. We now have the infrastructure in place to perform novel and unique high-impact experiments on collision-less shocks at the LAPD.

Niemann, Christoph [UCLA, CA (United States); Gekelman, W. [UCLA, CA (United States); Winske, D. [LANL, NM (United States); Larsen, D. [LLNL, CA (United States)

2012-12-14T23:59:59.000Z

205

Robust relativistic electron mirrors in laser wakefields for enhanced Thomson backscattering  

SciTech Connect (OSTI)

By adopting an up-ramp density profile, we propose to generate relativistic electron mirrors from laser-driven underdense plasma waves, which are insensitive to finite thermal temperature within a certain range. Along the density ramp, premature wavebreaking due to thermal effects is shown to be well mitigated. Under sufficiently high amplitudes of wake excitation, overcritical dense electron mirrors can pile up when approaching the end of the up-ramp. The consequent mirror speed can be stably driven to the group velocity of the laser propagating in a corresponding uniform plasma. Compared with using purely uniform but thermal plasmas, the present thermal-insensitive mirrors can provide enhanced scattering efficiency and spectral upshift for a counter-propagating probe pulse. These observations are confirmed by multi-dimensional particle-in-cell simulations.

Mu, Jie; Li, Fei-Yu; Zeng, Ming; Chen, Min [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)] [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sheng, Zheng-Ming [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, Jie [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China)

2013-12-23T23:59:59.000Z

206

PUBLISHED ONLINE: 19 AUGUST 2012 | DOI: 10.1038/NPHYS2390 Dynamics of relativistic transparency and optical  

E-Print Network [OSTI]

accelerators, X-ray sources and techniques for controlling the shape and contrast of intense laser pulses. W opaque to laser light. However, when the light is of sufficient intensity to drive electrons-overdense regime of relativistic plasmas, which should be useful in the development of laser-driven particle

Loss, Daniel

207

Selective ion source  

DOE Patents [OSTI]

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

Leung, K.N.

1996-05-14T23:59:59.000Z

208

Selective ion source  

DOE Patents [OSTI]

A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

209

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 55, NO. 4, APRIL 2008 1795 Reaching Criterion of a Three-Phase Voltage-Source  

E-Print Network [OSTI]

is useful for analyzing the global stability of multiphase inverters, potentially leading to advanced of a Three-Phase Voltage-Source Inverter Operating With Passive and Nonlinear Loads and Its Impact on Global functions (CLFs) to analyze the impacts of passive (RL and RC) and nonlinear (diode rectifier) loads

Mazumder, Sudip K.

210

Fast neutron production from lithium converters and laser driven protons  

SciTech Connect (OSTI)

Experiments to generate neutrons from the {sup 7}Li(p,n){sup 7}Be reaction with 60 J, 180 fs laser pulses have been performed at the Texas Petawatt Laser Facility at the University of Texas at Austin. The protons were accelerated from the rear surface of a thin target membrane using the target-normal-sheath-acceleration mechanism. The neutrons were generated in nuclear reactions caused by the subsequent proton bombardment of a pure lithium foil of natural isotopic abundance. The neutron energy ranged up to 2.9 MeV. The total yield was estimated to be 1.6 × 10{sup 7} neutrons per steradian. An extreme ultra-violet light camera, used to image the target rear surface, correlated variations in the proton yield and peak energy to target rear surface ablation. Calculations using the hydrodynamics code FLASH indicated that the ablation resulted from a laser pre-pulse of prolonged intensity. The ablation severely limited the proton acceleration and neutron yield.

Storm, M.; Jiang, S.; Wertepny, D.; Orban, C.; Morrison, J.; Willis, C.; McCary, E.; Balencourt, P.; Snyder, J.; Chowdhury, E.; Freeman, R. R.; Akli, K. [Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States)] [Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States); Bang, W.; Gaul, E.; Dyer, G.; Ditmire, T. [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)

2013-05-15T23:59:59.000Z

211

Single shot cell irradiations with laser-driven protons  

SciTech Connect (OSTI)

Ion beams are relevant for radiobiological studies in basic research and for application in tumor therapy. Here we present a method to generate nanosecond proton bunches with single shot doses of up to 7 Gray by a tabletop high-power laser. Although in their infancy, laser-ion accelerators allow studying fast radiobiological processes at small-scale laboratories as exemplarily demonstrated by measurements of the relative biological effectiveness of protons in human tumor cells.

Humble, N.; Schmid, T. E.; Zlobinskaya, O.; Wilkens, J. J. [Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München (Germany)] [Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München (Germany); Allinger, K.; Hilz, P.; Ma, W.; Reinhardt, S. [Physics Department, Ludwig-Maximilians-Universität München (Germany)] [Physics Department, Ludwig-Maximilians-Universität München (Germany); Bin, J.; Kiefer, D.; Schreiber, J. [Max Planck Institute of Quantum Optics, Garching (Germany)] [Max Planck Institute of Quantum Optics, Garching (Germany); Drexler, G. A.; Friedl, A. [Department of Radiation Oncology, Ludwig-Maximilians-Universität München (Germany)] [Department of Radiation Oncology, Ludwig-Maximilians-Universität München (Germany)

2013-07-26T23:59:59.000Z

212

Sinterable powders from laser driven reactions : final report  

E-Print Network [OSTI]

Extremely fine, uniform ceramic powders have been synthesized from Sil4 NH3 and C2H4 gas phase reactants that are heated by absorbing optical energy emitted from a C02 laser. Resulting Si, Si3N4 and SiC powders have been ...

Haggerty, John Scarseth

1981-01-01T23:59:59.000Z

213

Using laser-driven neutrons to stop nuclear smugglers  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdates byUser GuideHadoopUsing

214

A study on prevention of an electric discharge at an extraction electrode of an electron cyclotron resonance ion source for cancer therapy  

SciTech Connect (OSTI)

A compact ECR ion source has utilized for carbon radiotherapy. In order to increase beam intensity with higher electric field at the extraction electrode and be better ion supply stability for long periods, electric geometry and surface conditions of an extraction electrode have been studied. Focusing attention on black deposited substances on the extraction electrode, which were observed around the extraction electrode after long-term use, the relation between black deposited substances and the electrical insulation property is investigated. The black deposited substances were inspected for the thickness of deposit, surface roughness, structural arrangement examined using Raman spectroscopy, and characteristics of electric discharge in a test bench, which was set up to simulate the ECR ion source.

Kishii, Y., E-mail: Ando.Yasuto@ct.MitsubishiElectric.co.jp; Kawasaki, S. [Energy Systems Center, Mitsubishi Electric Corporation, 1-1-2 Wadasaki-cho, Hyogo-ku, Kobe 652-8555 (Japan)] [Energy Systems Center, Mitsubishi Electric Corporation, 1-1-2 Wadasaki-cho, Hyogo-ku, Kobe 652-8555 (Japan); Kitagawa, A.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)] [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Uchida, T. [Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan) [Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan); Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan)

2014-02-15T23:59:59.000Z

215

Terahertz radiation as a bunch diagnostic for laser-wakefield-accelerated electron bunches  

SciTech Connect (OSTI)

Experimental results are reported from two measurement techniques (semiconductor switching and electro-optic sampling) that allow temporal characterization of electron bunches produced by a laser-driven plasma-based accelerator. As femtosecond electron bunches exit the plasma-vacuum interface, coherent transition radiation (at THz frequencies) is emitted. Measuring the properties of this radiation allows characterization of the electron bunches. Theoretical work on the emission mechanism is presented, including a model that calculates the THz wave form from a given bunch profile. It is found that the spectrum of the THz pulse is coherent up to the 200 {micro}m thick crystal (ZnTe) detection limit of 4 THz, which corresponds to the production of sub-50 fs (rms) electron bunch structure. The measurements demonstrate both the shot-to-shot stability of bunch parameters that are critical to THz emission (such as total charge and bunch length), as well as femtosecond synchronization among bunch, THz pulse, and laser beam.

van Tilborg, Jeroen; Schroeder, Carl; Filip, Catalin; Toth, Csaba; Geddes, Cameron; Fubiani, Gwenael; Esarey, Eric; Leemans, Wim

2011-06-17T23:59:59.000Z

216

Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor  

SciTech Connect (OSTI)

A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

2014-03-15T23:59:59.000Z

217

Compact x-ray source and panel  

DOE Patents [OSTI]

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

218

Non-Markovian response of ultrafast coherent electronic ring currents in chiral aromatic molecules in a condensed phase  

SciTech Connect (OSTI)

Results of a theoretical study on non-Markov response for femtosecond laser-driven coherent ring currents in chiral aromatic molecules embedded in a condensed phase are presented. Coherent ring currents are generated by coherent excitation of a pair of quasi-degenerated ?-electronic excited states. The coherent electronic dynamical behaviors are strongly influenced by interactions between the electronic system and phonon bath in a condensed phase. Here, the bath correlation time is not instantaneous but should be taken to be a finite time in ultrashort time-resolved experiments. In such a case, Markov approximation breaks down. A hierarchical master equation approach for an improved semiclassical Drude dissipation model was adopted to examine the non-Markov effects on ultrafast coherent electronic ring currents of (P)-2,2{sup ?}-biphenol in a condensed phase. Time evolution of the coherent ring current derived in the hierarchical master equation approach was calculated and compared with those in the Drude model in the Markov approximation and in the static limit. The results show how non-Markovian behaviors in quantum beat signals of ring currents depend on the Drude bath damping constant. Effects of temperatures on ultrafast coherent electronic ring currents are also clarified.

Mineo, H. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)] [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Lin, S. H. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Department of Applied Chemistry, Institute of Molecular Science and Center for Interdisciplinary Molecular Science, National Chiao-Tung University, Hsin-Chu 300, Taiwan (China); Fujimura, Y. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China) [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Xu, J. [Department of Chemistry, Nankai University, Tianjin 300071 (China) [Department of Chemistry, Nankai University, Tianjin 300071 (China); Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Xu, R. X. [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yan, Y. J. [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong) [Department of Chemistry, Hong Kong University of Science and Technology, Kowloon (Hong Kong); Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2013-12-07T23:59:59.000Z

219

Solving the Accelerator-Condenser Coupling Problem in a Nanosecond Dynamic Transmission Electron Microscope  

SciTech Connect (OSTI)

We describe a modification to a transmission electron microscope (TEM) that allows it to briefly (using a pulsed-laser-driven photocathode) operate at currents in excess of 10 mA while keeping the effects of condenser lens aberrations to a minimum. This modification allows real-space imaging of material microstructure with a resolution of order 10 nm over regions several {micro}m across with an exposure time of 15 ns. This is more than 6 orders of magnitude faster than typical video-rate TEM imaging. The key is the addition of a weak magnetic lens to couple the large-diameter high-current beam exiting the accelerator into the acceptance aperture of a conventional TEM condenser lens system. We show that the performance of the system is essentially consistent with models derived from ray tracing and finite element simulations. The instrument can also be operated as a conventional TEM by using the electron gun in a thermionic mode. The modification enables very high electron current densities in {micro}m-sized areas and could also be used in a non-pulsed system for high-throughput imaging and analytical TEM.

Reed, B W; LaGrange, T; Shuttlesworth, R M; Gibson, D J; Campbell, G H; Browning, N D

2009-12-29T23:59:59.000Z

220

Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences  

E-Print Network [OSTI]

The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide bandwidth (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effec...

Biri, S; Muramatsu, M; Drentje, A G; Rácz, R; Yano, K; Kato, Y; Sasaki, N; Takasugi, W

2015-01-01T23:59:59.000Z

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221

Simulations of laser-wakefield acceleration with external electron-bunch injection for REGAE experiments at DESY  

SciTech Connect (OSTI)

We present particle-in-cell simulations for future laser-plasma wakefield experiments with external bunch injection at the REGAE accelerator facility at DESY, Hamburg, Germany. Two effects have been studied in detail: emittance evolution of electron bunches externally injected into a wake, and longitudinal bunch compression inside the wakefield. Results show significant transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This might introduce the necessity to include beam-matching sections upstream of each plasma-accelerator section with fundamental implications on the design of staged laser wakefield accelerators. When externally injected at the zero-field crossing of the laser-driven wake, the electron bunch may undergo significant compression in longitudinal direction and be accelerated simultaneously due to the gradient in the acting force. The mechanism would allow for production of single high-energy, ultra-short (on the order of one femtosecond) bunches at REGAE. The optimal conditions for maximal bunch compression are discussed in the presented studies.

Grebenyuk, Julia; Mehrling, Timon; Tsung, Frank S.; Floettman, Klaus; Osterhoff, Jens [Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Institut fuer Experimentalphysik, Universitaet Hamburg, 22761 Hamburg (Germany); University of California, Los Angeles, CA 90095 (United States); Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg (Germany); Institut fuer Experimentalphysik, Universitaet Hamburg, 22761 Hamburg (Germany)

2012-12-21T23:59:59.000Z

222

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,Physics Diagnostics UW Madison

223

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,Physics Diagnostics UW MadisonDiamondoid

224

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,Physics Diagnostics UW

225

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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226

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData FilesShape,Physics Diagnostics UWDiamondoid Monolayers

227

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: CrudeOfficeNERSC Helps Develop Di-Jia LiuConductors

228

Diamondoid Monolayers as Monochromatic Electron Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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229

Ultrafast Time-Resolved Electron Diffraction with Megavolt Electron Beams  

SciTech Connect (OSTI)

An rf photocathode electron gun is used as an electron source for ultrafast time-resolved pump-probe electron diffraction. We observed single-shot diffraction patterns from a 160 nm Al foil using the 5.4 MeV electron beam from the Gun Test Facility at the Stanford Linear Accelerator. Excellent agreement with simulations suggests that single-shot diffraction experiments with a time resolution approaching 100 fs are possible.

Hastings, J.B.; /SLAC; Rudakov, F.M.; /Brown U.; Dowell, D.H.; Schmerge, J.F.; /SLAC; Cardoza, J.D.; /Brown U.; Castro, J.M.; Gierman, S.M.; Loos, H.; /SLAC; Weber, P.M.; /Brown U.

2006-10-24T23:59:59.000Z

230

Electron donor-dependent radionuclide reduction and nanoparticle...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

size were observed, the association of UO2 nanoparticles with an exopolymeric substance (EPS) was observed and found to be independent of electron donor source. Electron...

231

NEWS & VIEWS Radiation SouRCES  

E-Print Network [OSTI]

NEWS & VIEWS Radiation SouRCES Electrons and lasers sing THz tune gwyn P. Williams is in the Free Bielawski and colleagues describe the ability to coherently control the radiative behaviour of the electrons a bright, tunable source of radiation in the difficult-to-reach terahertz region of the electromagnetic

Loss, Daniel

232

Electron Accelerator ight it be possible to com-  

E-Print Network [OSTI]

to micron wave- lengths for a laser-driven particle ac- celerator. In essence, a linear accel- erator micro- and nanoscale manuf&ring tech- niques to produce tabletop or even pocket-size particle-energyelectrons are acceler- ators costing millions if not billions of dollars that are availableto a very limited clientele

Byer, Robert L.

233

Solenoid and monocusp ion source  

DOE Patents [OSTI]

An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

1997-10-07T23:59:59.000Z

234

DOCUMENTATION OF ELECTRONIC In-text Citations  

E-Print Network [OSTI]

DOCUMENTATION OF ELECTRONIC SOURCES IN MLA In-text Citations In-text citations in MLA format of the message. Other Resources about On-line Citations 1.ONLINE! - Using MLA Style to Cite and Document Sources

deYoung, Brad

235

Free electron laser  

DOE Patents [OSTI]

A high gain, single-pass free electron laser formed of a high brilliance electron injector source, a linear accelerator which imparts high energy to the electron beam, and an undulator capable of extremely high magnetic fields, yet with a very short period. The electron injector source is the first stage (gap) of the linear accelerator or a radial line transformer driven by fast circular switch. The linear accelerator is formed of a plurality of accelerating gaps arranged in series. These gaps are energized in sequence by releasing a single pulse of energy which propagates simultaneously along a plurality of transmission lines, each of which feeds the gaps. The transmission lines are graduated in length so that pulse power is present at each gap as the accelerated electrons pass therethrough. The transmission lines for each gap are open circuited at their ends. The undualtor has a structure similar to the accelerator, except that the transmission lines for each gap are substantially short circuited at their ends, thus converting the electric field into magnetic field. A small amount of resistance is retained in order to generate a small electric field for replenishing the electron bunch with the energy lost as it traverses through the undulator structure.

Villa, Francesco (Alameda, CA)

1990-01-01T23:59:59.000Z

236

Wisconsin SRF Electron Gun Commissioning  

SciTech Connect (OSTI)

The University of Wisconsin has completed fabrication and commissioning of a low frequency (199.6 MHz) superconducting electron gun based on a quarter wave resonator (QWR) cavity. Its concept was optimized to be the source for a CW free electron laser facility. The gun design includes active tuning and a high temperature superconducting solenoid. We will report on the status of the Wisconsin SRF electron gun program, including commissioning experience and first beam measurements.

Bisognano, Joseph J. [University of Wisconsin-Madison; Bissen, M. [University of Wisconsin-Madison; Bosch, R. [University of Wisconsin-Madison; Efremov, M. [University of Wisconsin-Madison; Eisert, D. [University of Wisconsin-Madison; Fisher, M. [University of Wisconsin-Madison; Green, M. [University of Wisconsin-Madison; Jacobs, K. [University of Wisconsin-Madison; Keil, R. [University of Wisconsin-Madison; Kleman, K. [University of Wisconsin-Madison; Rogers, G. [University of Wisconsin-Madison; Severson, M. [University of Wisconsin-Madison; Yavuz, D. D. [University of Wisconsin-Madison; Legg, Robert A. [JLAB; Bachimanchi, Ramakrishna [JLAB; Hovater, J. Curtis [JLAB; Plawski, Tomasz [JLAB; Powers, Thomas J. [JLAB

2013-12-01T23:59:59.000Z

237

SYNCHROTRON RADIATION SOURCES  

SciTech Connect (OSTI)

Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

HULBERT,S.L.; WILLIAMS,G.P.

1998-07-01T23:59:59.000Z

238

Photon Source Parameters  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter |Photoinduced electronPhoton Source

239

Three chamber negative ion source  

DOE Patents [OSTI]

It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

1983-11-10T23:59:59.000Z

240

Long Plasma Source for Heavy Ion Beam Charge Neutralization  

E-Print Network [OSTI]

neutralizing plasma column the heavy ion beam can focus to aPlasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus

Efthimion, P.C.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

E-Print Network 3.0 - american electronics association Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

impulsive electron events were associated with solar type III radio bursts (Figure le-lg) observed... Energetic Electrons Accelerated in Solar Particle Events ... Source:...

242

E-Print Network 3.0 - auroral electron acceleration Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and vice versa. 4... of isolated auroral arcs. This means that upgoing electron beams (upward acceleration re- gions) can exist... electron ... Source: Ecole Polytechnique,...

243

E-Print Network 3.0 - auger electron emitting Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

high yield of Auger electrons originating from carbon surface atoms is observed... V intensity(arbitraryunits) electron energy (eV) ... Source: Groningen, Rijksuniversiteit -...

244

Electronic imaging system and technique  

DOE Patents [OSTI]

A method and system for viewing objects obscurred by intense plasmas or flames (such as a welding arc) includes a pulsed light source to illuminate the object, the peak brightness of the light reflected from the object being greater than the brightness of the intense plasma or flame; an electronic image sensor for detecting a pulsed image of the illuminated object, the sensor being operated as a high-speed shutter; and electronic means for synchronizing the shutter operation with the pulsed light source.

Bolstad, J.O.

1984-06-12T23:59:59.000Z

245

Hot electron production and heating by hot electrons in fast ignitor research  

SciTech Connect (OSTI)

In an experimental study of the physics of fast ignition the characteristics of the hot electron source at laser intensities up to 10(to the 20th power) Wcm{sup -2} and the heating produced at depth by hot electrons have been measured. Efficient generation of hot electrons but less than the anticipated heating have been observed.

Key, M.H.; Estabrook, K.; Hammel, B. [and others

1997-12-01T23:59:59.000Z

246

Electron temperature of Titan's sunlit ionosphere M. Galand,1  

E-Print Network [OSTI]

Electron temperature of Titan's sunlit ionosphere M. Galand,1 R. V. Yelle,2 A. J. Coates,3 H spacecraft and assess the ionization and electron heating sources in Titan's sunlit ionosphere. We compare CAPS electron spectra with spectra produced by an electron transport model based on the INMS neutral

Yelle, Roger V.

247

Electron Impedances  

SciTech Connect (OSTI)

It is only recently, and particularly with the quantum Hall effect and the development of nanoelectronics, that impedances on the scale of molecules, atoms and single electrons have gained attention. In what follows the possibility that characteristic impedances might be defined for the photon and the single free electron is explored is some detail, the premise being that the concepts of electrical and mechanical impedances are relevant to the elementary particle. The scale invariant quantum Hall impedance is pivotal in this exploration, as is the two body problem and Mach's principle.

P Cameron

2011-12-31T23:59:59.000Z

248

Resonant electron-CF collision processes  

SciTech Connect (OSTI)

Electronic structure methods are combined with variationalfixed-nuclei electron scattering calculations and nuclear dynamicsstudies to characterize resonant vibrational excitation and electronattachment processes in collisions between low-energy electrons and CFradicals. Several low-lying negative ion states are found which give riseto strong vibrational excitation and which are expected to dominate thelow-energy electron scattering cross sections. We have also studiedseveral processes which could lead to production of negative ions (F- andC-), However, in contrast to other recent predictions, we do not find CFin itsground state to be a significant source of negative ion productionwhen interacting with thermal electrons.

Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.

2005-03-18T23:59:59.000Z

249

Dispersion compensation for attosecond electron pulses  

SciTech Connect (OSTI)

We propose a device to compensate for the dispersion of attosecond electron pulses. The device uses only static electric and magnetic fields and therefore does not require synchronization to the pulsed electron source. Analogous to the well-known optical dispersion compensator, an electron dispersion compensator separates paths by energy in space. Magnetic fields are used as the dispersing element, while a Wien filter is used for compensation of the electron arrival times. We analyze a device with a size of centimeters, which can be applied to ultrafast electron diffraction and microscopy, and fundamental studies.

Hansen, Peter; Baumgarten, Cory; Batelaan, Herman; Centurion, Martin [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

2012-08-20T23:59:59.000Z

250

Radiochemical Transformation of High Pressure Methane under Gamma, Electron, and Neutron Irradiation  

E-Print Network [OSTI]

The chemical effects of irradiation on high pressure methane and noble gas mixtures were investigated using gamma, electron beam, and neutron irradiation sources. The gamma source used was the La-140 source from the Nuclear Science Center (NSC...

Clemens, Jeffrey Tyler

2014-05-01T23:59:59.000Z

251

Accelerator Sources for THz science: A Review  

SciTech Connect (OSTI)

Free Electron Lasers have been around since 1977 providing not only a test bed for the physics of FELs and electron/photon interactions but as a workhorse of scientific research. More than 30 FELs are presently operating around the world spanning a wavelength range from the millimeter region to the hard x-ray using direct current and rf linear accelerators or storage rings as electron sources. The characteristics that have driven the development of these sources are the desire for high peak and average power, high micropulse energies, wavelength tunability, timing flexibility, and wavelengths that are unavailable from more conventional laser sources. Operation of FELs in the far infrared to terahertz regime poses special challenges which have been and are being addressed at a number of facilities around the world. This paper will review a number of former and existing FELs operating in this regime and discuss future efforts. Broadband collective radiation from relativistic electrons also plays a significant role in the production of FIR/THz radiation and several groups are taking advantage of this source for users. Applications for use of the radiation have evolved from simple imaging to complex pump probe tests of insulator/metal transitions and energy flow in organic molecules. We will discuss the technologies for generating the IR/FIR/THz radiation and cover some of the unique applications of such sources.

Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-01-01T23:59:59.000Z

252

Ultra-bright pulsed electron beam with low longitudinal emittance  

DOE Patents [OSTI]

A high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography has been described. The source makes use of Cs atoms in an atomic beam. The source is cycled beginning with a laser pulse that excites a single Cs atom on average to a band of high-lying Rydberg nP states. The resulting valence electron Rydberg wave packet evolves in a nearly classical Kepler orbit. When the electron reaches apogee, an electric field pulse is applied that ionizes the atom and accelerates the electron away from its parent ion. The collection of electron wave packets thus generated in a series of cycles can occupy a phase volume near the quantum limit and it can possess very high brightness. Each wave packet can exhibit a considerable degree of coherence.

Zolotorev, Max (Oakland, CA)

2010-07-13T23:59:59.000Z

253

A Polarized Positron Source for CEBAF  

SciTech Connect (OSTI)

A compact polarized positron source for Jefferson Lab is discussed. This scheme relies upon a high polarization (85%), high current (1 mA), low-energy (<100 MeV) electron beam to generate polarized positrons in a conversion target via polarized bremsstrahlung and pair creation. GEANT4 is used to simulate source distributions suitable for a CEBAF-like injector with positron polarization approx60% and nano-Ampere intensity. An experiment to test this scheme is outlined.

Dumas, J. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3/CNRS-Universite Joseph Fourier-INP, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Grames, J. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Voutier, E. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3/CNRS-Universite Joseph Fourier-INP, 53, rue des Martyrs, 38026 Grenoble Cedex (France)

2009-09-02T23:59:59.000Z

254

Electrolytes for power sources  

DOE Patents [OSTI]

Electrolytes are disclosed for power sources, particularly alkaline and acidic power sources, comprising benzene polysulfonic acids and benzene polyphosphonic acids or salts of such acids. 7 figures.

Doddapaneni, N.; Ingersoll, D.

1995-01-03T23:59:59.000Z

255

Protected Water Sources (Iowa)  

Broader source: Energy.gov [DOE]

This chapter designates protected water sources, which are subject to additional special conditions regarding water use. Permit applications for water withdrawals from these sources may still be...

256

Electron CoolingElectron Cooling Sergei Nagaitsev  

E-Print Network [OSTI]

Electron CoolingElectron Cooling Sergei Nagaitsev FNAL - AD April 28, 2005 #12;Electron Cooling methods must "get around the theorem" e.g. by pushing phase-space around. #12;Electron Cooling - Nagaitsev 3 TodayToday''s Menus Menu What is cooling? Types of beam cooling Electron cooling Conclusions #12

Fermilab

257

E-Print Network 3.0 - alpha tagged x-ray Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ion -Cu K-alpha imaging system -X-ray... and for the optimisation of high power laser-driven ion and X-ray sources. ... Source: Strathclyde, University of - Department...

258

X-ray lithography source  

DOE Patents [OSTI]

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.

1991-12-31T23:59:59.000Z

259

X-ray lithography source  

DOE Patents [OSTI]

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

1991-01-01T23:59:59.000Z

260

Polyplanar optical display electronics  

SciTech Connect (OSTI)

The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. The prototype ten inch display is two inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. In order to achieve a long lifetime, the new display uses a 100 milliwatt green solid-state laser (10,000 hr. life) at 532 nm as its light source. To produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments. In order to use the solid-state laser as the light source and also fit within the constraints of the B-52 display, the Digital Micromirror Device (DMD{trademark}) circuit board is removed from the Texas Instruments DLP light engine assembly. Due to the compact architecture of the projection system within the display chassis, the DMD{trademark} chip is operated remotely from the Texas Instruments circuit board. The authors discuss the operation of the DMD{trademark} divorced from the light engine and the interfacing of the DMD{trademark} board with various video formats (CVBS, Y/C or S-video and RGB) including the format specific to the B-52 aircraft. A brief discussion of the electronics required to drive the laser is also presented.

DeSanto, L.; Biscardi, C. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology

1997-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

ELECTRONIC WARFARE NOVEMBER 2012  

E-Print Network [OSTI]

FM 3-36 ELECTRONIC WARFARE NOVEMBER 2012 DISTRIBUTION RESTRICTION: Approved for public release Electronic Warfare Contents Page PREFACE..............................................................................................................iv Chapter 1 ELECTRONIC WARFARE OVERVIEW ............................................................ 1

US Army Corps of Engineers

262

A threshold for laser-driven linear particle acceleration in unbounded vacuum  

E-Print Network [OSTI]

We hypothesize that a charged particle in unbounded vacuum can be substantially accelerated by a force linear in the electric field of a propagating electromagnetic wave only if the accelerating field is capable of bringing ...

Wong, Liang Jie

2011-01-01T23:59:59.000Z

263

Quantification of Uncertainties Due to Opacities in a Laser-Driven Radiative-Shock Problem  

E-Print Network [OSTI]

......................................................................... 44 3.2 Introduction to Uncertain Parameters in Opacity Calculations ......................... 45 3.3 Analysis of Relevant Uncertain Data Used in the CRASH Code ..................... 45 3.3.1 Evaluation of Oscillator Strengths... with Adjusted Xenon Opacity .......... 71 5.1.3 Results Using Oscillator Strengths ............................................................ 80 5.1.4 Results Using Oscillator Strengths with Adjusted Xenon Opacity ........... 89 5.2 Results for the 1-D...

Hetzler, Adam C

2013-03-28T23:59:59.000Z

264

Time- and spectrally resolved measurements of laser-driven hohlraum radiation  

SciTech Connect (OSTI)

At the GSI Helmholtz center for heavy-ion research combined experiments with heavy ions and laser-produced plasmas are investigated. As a preparation to utilize indirectly heated targets, where a converter hohlraum provides thermal radiation to create a more homogeneous plasma, this converter target has to be characterized. In this paper the latest results of these measurements are presented. Small spherical cavities with diameters between 600 and 750 {mu}m were heated with laser energies up to 30 J at 532-nm wavelength. Radiation temperatures could be determined by time-resolved as well as time-integrated diagnostics, and maximum values of up to 35 eV were achieved.

Hessling, T.; Blazevic, A.; Stoehlker, T. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Frank, A.; Kraus, D.; Roth, M.; Schaumann, G.; Schumacher, D.; Hoffmann, D. H. H. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany)

2011-07-15T23:59:59.000Z

265

Impedance-matching experiments using high-pressure, laser-driven shock waves  

SciTech Connect (OSTI)

A high-power laser was used to produce shock waves with pressures of 300 to 700 GPa. A series of impedance-matching experiments on aluminum-copper systems with 10% accuracy indicate several areas in which the experiment can be improved to reduce the errors. Several such improvements are now being made, including upgrading both the laser and recording systems and modifying the target characterization techniques.

Veeser, L.R.; Reeves, G.A.; Holmes, N.C.; Trainor, R.J.; Anderson, R.A.

1981-01-01T23:59:59.000Z

266

Laser-driven hole boring and gamma-ray emission in high-density plasmas  

E-Print Network [OSTI]

Ion acceleration in laser-produced dense plasmas is a key topic of many recent investigations thanks to its potential applications. Besides, at forthcoming laser intensities ($I \\gtrsim 10^{23} \\text{W}\\,\\text{cm}^{-2}$) interaction of laser pulses with plasmas can be accompanied by copious gamma-ray emission. Here we demonstrate the mutual influence of gamma-ray emission and ion acceleration during relativistic hole boring in high-density plasmas with ultra-intense laser pulses. If gamma-ray emission is abundant, laser pulse reflection and hole-boring velocity are lower and gamma-ray radiation pattern is narrower than in the case of low emission. Conservation of energy and momentum allows one to elucidate the effects of gamma-ray emission which are more pronounced at higher hole-boring velocities.

Nerush, Evgeny

2014-01-01T23:59:59.000Z

267

Instability, mixing, and transition to turbulence in a laser-driven counterflowing shear experiment  

SciTech Connect (OSTI)

In a turbulence experiment conducted at the Omega Laser Facility [Boehly et al., Opt. Commun. 133, 495 (1997)

Doss, F. W.; Loomis, E. N.; Welser-Sherrill, L.; Fincke, J. R.; Flippo, K. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Keiter, P. A. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2013-01-15T23:59:59.000Z

268

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility  

SciTech Connect (OSTI)

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in benchmarking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240?eV. This creates a subsonic diffusive Marshak wave, which propagates into a high atomic number Ta{sub 2}O{sub 5} aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range of x-ray measurements that absolutely quantify the energetics and radiation partition inside the target.

Moore, A. S., E-mail: alastair.moore@physics.org; Graham, P.; Comley, A. J.; Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading RG7 4PR (United Kingdom); Cooper, A. B. R.; Schneider, M. B.; MacLaren, S.; Lu, K.; Seugling, R.; Satcher, J.; Klingmann, J.; Marrs, R.; May, M.; Widmann, K.; Glendinning, G.; Castor, J.; Sain, J.; Baker, K.; Hsing, W. W.; Young, B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2014-06-15T23:59:59.000Z

269

Laser-driven search of axion-like particles including vacuum polarization effects  

E-Print Network [OSTI]

Oscillations of photons into axion-like particles in a high-intensity laser field are investigated. Nonlinear QED effects are considered through the low energy behavior of the vacuum polarization tensor, which is derived from the Euler-Heisenberg Lagrangian in the one-loop and weak field approximations. The expressions obtained in this framework are applied to the configuration in which the strong background field is a circularly polarized monochromatic plane wave. The outcomes of this analysis reveal that, in the regime of low energy-momentum transfer, the axion field induces a chiral-like birefringence and dichroism in the vacuum which is not manifest in a pure QED context. The corresponding ellipticity and angular rotation of the polarization plane are also determined. We take advantage of such observables to impose exclusion limits on the axion parameters. Our predictions cover axion masses for which a setup based on dipole magnets provides less stringent constraints. Possible experimental scenarios in which our results could be tested are also discussed.

Selym Villalba-Chávez

2014-02-26T23:59:59.000Z

270

First time nuclear material detection by one short-pulse-laser-driven neutron  

E-Print Network [OSTI]

counters; one detector containing a 2 kg sample of depleted uranium, and the other one empty for background comparison. A single shot interrogation of the depleted uranium sample, showed a clear signal from the delayed neutrons in the detector with uranium, compared with the background, and with the typical time

Kurien, Susan

271

Laser-driven, magnetized quasi-perpendicular collisionless shocks on the Large Plasma Devicea)  

E-Print Network [OSTI]

and Astronomy, University of California - Los Angeles, Los Angeles, California 90095, USA 2 Los Alamos National Plasma Device [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] at the University of California, Los environments, including supernovae remnants, coronal mass ejections, the solar wind, and iono- spheric

California at Los Angles, University of

272

First time nuclear material detection by one short-pulse-laser-driven  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibilityField OfficeFirmFirst ProofgaseousFirst round of

273

First time nuclear material detection by one short-pulse-laser-driven  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series toESnet4:EpitaxialtransatlanticUnified|North America |Proofneutron

274

Catalog of supersoft X-ray sources  

E-Print Network [OSTI]

This catalog comprises an up-to-date (December 1999) list of luminous (>10^36 erg/s), binary supersoft X-ray sources. This electronic version (including the accompannying Web-pages) supersedes the printed version of Greiner (1996).

J. Greiner

2000-05-11T23:59:59.000Z

275

GEOMETRIC SOURCE SEPARATION: MERGING CONVOLUTIVE SOURCE  

E-Print Network [OSTI]

adaptive beamforming algorithms by a cross-power criteria, we gain new geometric source separation with convo- lutive blind source separation. We concentrate on cross-power spectral min- imization which is su to ambiguities in the choice of separating lters. There are in theory multiple lters that invert the room

Parra, Lucas C.

276

ccsd00001953, A comparative analysis of the electron energy  

E-Print Network [OSTI]

-1027, 11801 M#19;exico D. F., MEXICO E-mail: cgt@nuclear.inin.mx Abstract. To establish the electron energyccsd­00001953, version 1 ­ 22 Oct 2004 A comparative analysis of the electron energy distribution place in ECR plasma sources, where low pressure plasma is sustained by electron impact ionization

277

Unraveling resistive versus collisional contributions to relativistic electron beam stopping power in cold-solid and in warm-dense plasmas  

SciTech Connect (OSTI)

We present results on laser-driven relativistic electron beam propagation through aluminum samples, which are either solid and cold or compressed and heated by laser-induced shock. A full numerical description of fast electron generation and transport is found to reproduce the experimental absolute K{sub ?} yield and spot size measurements for varying target thicknesses, and to sequentially quantify the collisional and resistive electron stopping powers. The results demonstrate that both stopping mechanisms are enhanced in compressed Al samples and are attributed to the increase in the medium density and resistivity, respectively. For the achieved time- and space-averaged electronic current density, ?j{sub h}??8×10{sup 10}?A/cm{sup 2} in the samples, the collisional and resistive stopping powers in warm and compressed Al are estimated to be 1.5?keV/?m and 0.8?keV/?m, respectively. By contrast, for cold and solid Al, the corresponding estimated values are 1.1?keV/?m and 0.6?keV/?m. Prospective numerical simulations involving higher j{sub h} show that the resistive stopping power can reach the same level as the collisional one. In addition to the effects of compression, the effect of the transient behavior of the resistivity of Al during relativistic electron beam transport becomes progressively more dominant, and for a significantly high current density, j{sub h}?10{sup 12}?A/cm{sup 2}, cancels the difference in the electron resistive stopping power (or the total stopping power in units of areal density) between solid and compressed samples. Analytical calculations extend the analysis up to j{sub h}=10{sup 14}?A/cm{sup 2} (representative of the full-scale fast ignition scenario of inertial confinement fusion), where a very rapid transition to the Spitzer resistivity regime saturates the resistive stopping power, averaged over the electron beam duration, to values of ?1?keV/?m.

Vauzour, B. [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France) [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Laboratoire d'Optique Appliquée, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France); Debayle, A. [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain) [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain); CEA, DAM, DIF, F-91297 Arpajon (France); Vaisseau, X.; Hulin, S.; Nicolaï, Ph.; Dorchies, F.; Fourment, C.; D'Humières, E.; Tikhonchuk, V. T.; Santos, J. J., E-mail: santos.joao@celia.u-bordeaux1.fr [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Schlenvoigt, H.-P.; Baton, S. D.; Yahia, V. [LULI, Ecole Polytechnique, CNRS/CEA/UPMC, 91128 Palaiseau Cedex (France)] [LULI, Ecole Polytechnique, CNRS/CEA/UPMC, 91128 Palaiseau Cedex (France); Batani, D. [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France) [CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), Univ. Bordeaux, UMR 5107, F-33405 Talence (France); Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy); Honrubia, J. J. [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain)] [ETSI Aeronáuticos, Universidad Politécnica de Madrid, Madrid (Spain); Beg, F. N.; Chawla, S.; Jarrot, L. C. [University of California, San Diego, La Jolla, California 92093 (United States)] [University of California, San Diego, La Jolla, California 92093 (United States); Benocci, R.; Volpe, L. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy)] [Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy); and others

2014-03-15T23:59:59.000Z

278

Photo-stimulated low electron temperature high current diamond film field emission cathode  

DOE Patents [OSTI]

An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

Shurter; Roger Philips (Los Alamos, NM), Devlin; David James (Santa Fe, NM), Moody; Nathan Andrew (Los Alamos, NM), Taccetti; Jose Martin (Santa Fe, NM), Russell; Steven John (Los Alamos, NM)

2012-07-24T23:59:59.000Z

279

Ion-induced electron emission microscopy  

DOE Patents [OSTI]

An ion beam analysis system that creates multidimensional maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the secondary electrons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted secondary electrons are collected in a strong electric field perpendicular to the sample surface and (optionally) projected and refocused by the electron lenses found in a photon emission electron microscope, amplified by microchannel plates and then their exact position is sensed by a very sensitive X Y position detector. Position signals from this secondary electron detector are then correlated in time with nuclear, atomic or electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these secondary electrons in the fit place.

Doyle, Barney L. (Albuquerque, NM); Vizkelethy, Gyorgy (Albuquerque, NM); Weller, Robert A. (Brentwood, TN)

2001-01-01T23:59:59.000Z

280

Negative hydrogen ion sources for accelerators  

SciTech Connect (OSTI)

A variety of H{sup -} ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H{sup -} ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H{sup -} production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

Moehs, D.P.; /Fermilab; Peters, J.; /DESY; Sherman, J.; /Los Alamos

2005-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Portable thermo-photovoltaic power source  

DOE Patents [OSTI]

A miniature thermo-photovoltaic (TPV) device for generation of electrical power for use in portable electronic devices. A TPV power source is constructed to provide a heat source chemical reactor capable of using various fuels, such as liquid hydrocarbons, including but not limited to propane, LPG, butane, alcohols, oils and diesel fuels to generate a source of photons. A reflector dish guides misdirected photon energy from the photon source toward a photovoltaic array. A thin transparent protector sheet is disposed between the photon source and the array to reflect back thermal energy that cannot be converted to electricity, and protect the array from thermal damage. A microlens disposed between the protector sheet and the array further focuses the tailored band of photon energy from the photon source onto an array of photovoltaic cells, whereby the photon energy is converted to electrical power. A heat recuperator removes thermal energy from reactor chamber exhaust gases, preferably using mini- or micro-bellows to force air and fuel past the exhaust gases, and uses the energy to preheat the fuel and oxidant before it reaches the reactor, increasing system efficiency. Mini- or micro-bellows force ambient air through the system both to supply oxidant and to provide cooling. Finally, an insulator, which is preferably a super insulator, is disposed around the TPV power source to reduce fuel consumption, and to keep the TPV power source cool to the touch so it can be used in hand-held devices.

Zuppero, Anthony C. (Idaho Falls, ID); Krawetz, Barton (Idaho Falls, ID); Barklund, C. Rodger (Idaho Falls, ID); Seifert, Gary D. (Idaho Falls, ID)

1997-01-14T23:59:59.000Z

282

ATF Plasma Sources for Wakefield Electron Acceleration ATF User's Meeting  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre the Effects of GlobalASCR User FacilitiesBaslerfluxPlasma

283

PROGRESS AND FUTURE DIRECTIONS IN BRIGHTNESS ELECTRON BEAM SOURCES*  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheSteven Ashby Dr. Steven Para buscar una publicación,PROGRESS

284

The Electronic Origin of Photoinduced Strain | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 and NbSe2Different Impacts ofDepositedofModifying

285

ILC Electron Source Gets Help from JLab | Jefferson Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSL Bubblesstructure link to2, Issue 27,

286

Squeezing Out the Hidden Lives of Electrons | Advanced Photon Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSiteNeutron Scattering4 By I. Tudosa,Spreading an

287

Separation phenomenon in the Windowless Gaseous Tritium Source of KATRIN  

E-Print Network [OSTI]

Separation phenomenon in the Windowless Gaseous Tritium Source of KATRIN experiment. Ternary separa- tion. In the KATRIN experiment, in order to analyze the spectrum of electrons emmited by Tritium decay, it is very important to know the concentration distribution of Tritium along the source

Sharipov, Felix

288

Analysis of 3-panel and 4-panel microscale ionization sources  

SciTech Connect (OSTI)

Two designs of a microscale electron ionization (EI) source are analyzed herein: a 3-panel design and a 4-panel design. Devices were fabricated using microelectromechanical systems technology. Field emission from carbon nanotube provided the electrons for the EI source. Ion currents were measured for helium, nitrogen, and xenon at pressures ranging from 10{sup -4} to 0.1 Torr. A comparison of the performance of both designs is presented. The 4-panel microion source showed a 10x improvement in performance compared to the 3-panel device. An analysis of the various factors affecting the performance of the microion sources is also presented. SIMION, an electron and ion optics software, was coupled with experimental measurements to analyze the ion current results. The electron current contributing to ionization and the ion collection efficiency are believed to be the primary factors responsible for the higher efficiency of the 4-panel microion source. Other improvements in device design that could lead to higher ion source efficiency in the future are also discussed. These microscale ion sources are expected to find application as stand alone ion sources as well as in miniature mass spectrometers.

Natarajan, Srividya; Parker, Charles B.; Glass, Jeffrey T. [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Piascik, Jeffrey R.; Gilchrist, Kristin H. [Center for Materials and Electronic Technologies, RTI International, Research Triangle Park, North Carolina 27709 (United States); Stoner, Brian R. [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Center for Materials and Electronic Technologies, RTI International, Research Triangle Park, North Carolina 27709 (United States)

2010-06-15T23:59:59.000Z

289

DC source assemblies  

DOE Patents [OSTI]

Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

Campbell, Jeremy B; Newson, Steve

2013-02-26T23:59:59.000Z

290

Electron beam generation in Tevatron electron lenses  

SciTech Connect (OSTI)

New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.

Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; /Fermilab; Tiunov, M.; /Novosibirsk, IYF

2006-08-01T23:59:59.000Z

291

Note on RF Photo-Cathode Gun  

E-Print Network [OSTI]

Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

292

Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes  

E-Print Network [OSTI]

Design considerations for a laser-plasma linear collider,"E.Esarey, and W.P.Leemans, "Free-electron laser driven bythe LBNL laser-plasma accelerator," in Proc. Adv. Acc. Con.

Geddes, C.G.R.

2011-01-01T23:59:59.000Z

293

Compton backscattered collimated x-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

Ruth, R.D.; Huang, Z.

1998-10-20T23:59:59.000Z

294

Compton backscattered collmated X-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

2000-01-01T23:59:59.000Z

295

Compton backscattered collimated x-ray source  

DOE Patents [OSTI]

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

1998-01-01T23:59:59.000Z

296

NEW SOURCES OF RADIATION  

E-Print Network [OSTI]

Stanford Synchrotron Radiation Project Report No. 75/07.IBL 79M0733 Fig. 20. Radiation emission pattern by electronsWinick, Stanford Synchrotron Radiation Laboratory. Fig. 21.

Schimmerling, W.

2010-01-01T23:59:59.000Z

297

Calibration of a DSSSD detector with radioactive sources  

SciTech Connect (OSTI)

The energy calibration of a DSSSD is carried out with the spectra produced by a {sup 207}Bi conversion electron source, a {sup 137}Cs gamma source and a {sup 239}Pu/{sup 241}Am/{sup 244}Cm triple alpha source, as well as employing a precision pulse generator in the whole dynamic range. Multiplicity and coincidence of signals in different strips for the same event are also studied.

Guadilla, V.; Tain, J. L.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Rubio, B. [Instituto de Fisica Corpuscular, C.S.I.C.-Univ. Valencia, Ap 22085, E-46071, Valencia (Spain)

2013-06-10T23:59:59.000Z

298

A low-neutron background slow-positron source.  

SciTech Connect (OSTI)

The addition of a thermionic rf gun [1] and a photocathode rf gun will allow the Advanced Photon Source (APS) linear accelerator (linac) [2] [3] to become a free-electron laser (FEL) driver [4]. As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low neutron background.

White, M. M.

1998-10-09T23:59:59.000Z

299

Light sources based on semiconductor current filaments  

DOE Patents [OSTI]

The present invention provides a new type of semiconductor light source that can produce a high peak power output and is not injection, e-beam, or optically pumped. The present invention is capable of producing high quality coherent or incoherent optical emission. The present invention is based on current filaments, unlike conventional semiconductor lasers that are based on p-n junctions. The present invention provides a light source formed by an electron-hole plasma inside a current filament. The electron-hole plasma can be several hundred microns in diameter and several centimeters long. A current filament can be initiated optically or with an e-beam, but can be pumped electrically across a large insulating region. A current filament can be produced in high gain photoconductive semiconductor switches. The light source provided by the present invention has a potentially large volume and therefore a potentially large energy per pulse or peak power available from a single (coherent) semiconductor laser. Like other semiconductor lasers, these light sources will emit radiation at the wavelength near the bandgap energy (for GaAs 875 nm or near infra red). Immediate potential applications of the present invention include high energy, short pulse, compact, low cost lasers and other incoherent light sources.

Zutavern, Fred J. (Albuquerque, NM); Loubriel, Guillermo M. (Albuquerque, NM); Buttram, Malcolm T. (Sandia Park, NM); Mar, Alan (Albuquerque, NM); Helgeson, Wesley D. (Albuquerque, NM); O'Malley, Martin W. (Edgewood, NM); Hjalmarson, Harold P. (Albuquerque, NM); Baca, Albert G. (Albuquerque, NM); Chow, Weng W. (Cedar Crest, NM); Vawter, G. Allen (Albuquerque, NM)

2003-01-01T23:59:59.000Z

300

Dynamic radioactive particle source  

DOE Patents [OSTI]

A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

2012-06-26T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

SOURCE SELECTION INFORMATION -  

Office of Environmental Management (EM)

on Energy and Water Development U.S. House of Representatives The Honorable Lamar Alexander Ranking Member SOURCE SELECTION INFORMATION - SEE FEDERAL ACQUISITION...

302

SOURCE SELECTION INFORMATION -  

Energy Savers [EERE]

on Energy and Water Development U.S. House of Representatives The Honorable Lamar Alexander SOURCE SELECTION INFORMATION - SEE FEDERAL ACQUISITION REGULATION (FAR)...

303

Relativistic Electron Experiment for the Undergraduate Laboratory  

E-Print Network [OSTI]

We have developed an undergraduate laboratory experiment to make independent measurements of the momentum and kinetic energy of relativistic electrons from a \\beta -source. The momentum measurements are made with a magnetic spectrometer and a silicon surface-barrier detector is used to measure the kinetic energy. A plot of the kinetic energy as a function of momentum compared to the classical and relativistic predictions clearly shows the relativistic nature of the electrons. Accurate values for the rest mass of the electron and the speed of light are also extracted from the data.

Marvel, Robert E

2011-01-01T23:59:59.000Z

304

Ponderomotive phase plate for transmission electron microscopes  

DOE Patents [OSTI]

A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

Reed, Bryan W. (Livermore, CA)

2012-07-10T23:59:59.000Z

305

Controlling Graphene's Electronic Structure  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...

306

Plasma wake field XUV radiation source  

DOE Patents [OSTI]

A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.

Prono, Daniel S. (Los Alamos, NM); Jones, Michael E. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

307

E-Print Network 3.0 - angle-resolved electron energy Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

which electrons can bypass the energy gap by moving in surface states. The energy... by Hasan and Cava detected these unusual surface states in the ... Source: Petta, Jason -...

308

E-Print Network 3.0 - anisotropic electron drift Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

are like point... of the transport of charge carriers in a quasi bidimensional electron gas confined in a nanostructure. Index Terms Source: Mhats, Florian - Institut de...

309

Radiation Source Replacement Workshop  

SciTech Connect (OSTI)

This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

2010-12-01T23:59:59.000Z

310

Lithium ion sources  

E-Print Network [OSTI]

HIFAN 1866 Lithium ion sources by Prabir K. Roy, Wayne G.No. DE-AC02-05CH11231. Lithium ion sources Prabir K. RoyUSA Abstract A 10.9 cm diameter lithium alumino-silicate ion

Roy, Prabir K.

2014-01-01T23:59:59.000Z

311

Neutron sources and applications  

SciTech Connect (OSTI)

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01T23:59:59.000Z

312

Photonic crystal light source  

DOE Patents [OSTI]

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27T23:59:59.000Z

313

Piezotube borehole seismic source  

DOE Patents [OSTI]

A piezoelectric borehole source capable of permanent or semipermanent insertion into a well for uninterrupted well operations is described. The source itself comprises a series of piezoelectric rings mounted to an insulative mandrel internally sized to fit over a section of well tubing, the rings encased in a protective housing and electrically connected to a power source. Providing an AC voltage to the rings will cause expansion and contraction sufficient to create a sonic pulse. The piezoelectric borehole source fits into a standard well, and allows for uninterrupted pass-through of production tubing, and other tubing and electrical cables. Testing using the source may be done at any time, even concurrent with well operations, during standard production.

Daley, Tom M; Solbau, Ray D; Majer, Ernest L

2014-05-06T23:59:59.000Z

314

Pulsed ion beam source  

DOE Patents [OSTI]

An improved pulsed ion beam source having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center.

Greenly, John B. (Lansing, NY)

1997-01-01T23:59:59.000Z

315

Analysis Of Application Of Electronics In Exploration And Exploitation...  

Open Energy Info (EERE)

Of Electronics In Exploration And Exploitation Of Geothermal-Energy Sources In India Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Analysis Of...

316

Sources of the Radio Background Considered  

SciTech Connect (OSTI)

We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

2011-08-22T23:59:59.000Z

317

Electronics, Electrical Engineering  

E-Print Network [OSTI]

SCHOOL OF Electronics, Electrical Engineering and Computer Science IS IN YOUR HANDS THE FUTURE #12;SCHOOL OF Electronics, Electrical Engineering and Computer Science2 CAREERS IN ELECTRONICS, ELECTRICAL Belfast. Ranked among the top 100 in the world for Electrical and Electronic Engineering (QS World

318

ELECTRONIC CHARTS INTRODUCTION  

E-Print Network [OSTI]

199 CHAPTER 14 ELECTRONIC CHARTS INTRODUCTION 1400. The Importance of Electronic Charts Since. Electronic charts automate the process of integrating real-time positions with the chart display and allow is expected to take and plot a fix every three minutes. An electronic chart system can do it once per second

New Hampshire, University of

319

Advanced RF power sources for linacs  

SciTech Connect (OSTI)

In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

Wilson, P.B.

1996-10-01T23:59:59.000Z

320

Neutron sources: Present practice and future potential  

SciTech Connect (OSTI)

The present capability and future potential of accelerator-based monoenergetic and white neutron sources are outlined in the context of fundamental and applied neutron-nuclear research. The neutron energy range extends from thermal to 500 MeV, and the time domain from steady-state to pico-second pulsed sources. Accelerator technology is summarized, including the production of intense light-ion, heavy-ion and electron beams. Target capabilities are discussed with attention to neutron-producing efficiency and power-handling capabilities. The status of underlying neutron-producing reactions is summarized. The present and future use of neutron sources in: fundamental neutron-nuclear research, nuclear data acquisition, materials damage studies, engineering tests, and biomedical applications are discussed. Emphasis is given to current status, near-term advances well within current technology, and to long-range projections. 90 refs., 4 figs.

Cierjacks, S.; Smith, A.B.

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Plasma diagnostic tools for optimizing negative hydrogen ion sources  

SciTech Connect (OSTI)

The powerful diagnostic tool of optical emission spectroscopy is used to measure the plasma parameters in negative hydrogen ion sources based on the surface mechanism. Results for electron temperature, electron density, atomic-to-molecular hydrogen density ratio, and gas temperature are presented for two types of sources, a rf source and an arc source, which are currently under development for a neutral beam heating system of ITER. The amount of cesium in the plasma volume is obtained from cesium radiation: the Cs neutral density is five to ten orders of magnitude lower than the hydrogen density and the Cs ion density is two to three orders of magnitude lower than the electron density in front of the grid. It is shown that monitoring of cesium lines is very useful for monitoring the cesium balance in the source. From a line-ratio method negative ion densities are determined. In a well-conditioned source the negative ion density is of the same order of magnitude as the electron density and correlates with extracted current densities.

Fantz, U.; Falter, H.D.; Franzen, P.; Speth, E.; Hemsworth, R.; Boilson, D.; Krylov, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); CEA-Cadarache, EURATOM Association, F-13108 St. Paul-lez-Durance (France); Association EURATOM-DCU, PRL/NCST, Glasnevin, Dublin 13 (Ireland); RRC Kurchatov Institute, 1 Kurchatov Square, Moscow 123182 (Russian Federation)

2006-03-15T23:59:59.000Z

322

Tunable terahertz radiation source  

SciTech Connect (OSTI)

Terahertz radiation source and method of producing terahertz radiation, said source comprising a junction stack, said junction stack comprising a crystalline material comprising a plurality of self-synchronized intrinsic Josephson junctions; an electrically conductive material in contact with two opposing sides of said crystalline material; and a substrate layer disposed upon at least a portion of both the crystalline material and the electrically-conductive material, wherein the crystalline material has a c-axis which is parallel to the substrate layer, and wherein the source emits at least 1 mW of power.

Boulaevskii, Lev; Feldmann, David M; Jia, Quanxi; Koshelev, Alexei; Moody, Nathan A

2014-01-21T23:59:59.000Z

323

Microfabricated diffusion source  

DOE Patents [OSTI]

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Oborny, Michael C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

2008-07-15T23:59:59.000Z

324

Free electron laser using Rf coupled accelerating and decelerating structures  

DOE Patents [OSTI]

A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

325

A terahertz-driven electron gun  

E-Print Network [OSTI]

Electron sources at keV-MeV energies are indispensable for applications such as ultrafast electron diffraction, x-ray generation, and electron energy-loss spectroscopy. However, the accessibility and size of current accelerators based on radio-frequency (RF) technology are limited by the achievable electric fields. Terahertz based accelerators promise unprecedented compactness compared to current RF accelerators due to the intense electric fields that can be applied in the accelerating structures. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to a mean energy of 18 eV by a single-cycle THz field with peak electric field gradient of 72 MV/m at 1 kHz repetition rate. Scaling of the THz field into the gigavolt per meter regime would translate to electron energies of ~100 keV. Furthermore, in combination with the recent demonstration of a THz linear accelerator (linac), this is a milestone toward a millimeter- to centimeter-scale relativistic electron source.

Huang, W Ronny; Ravi, Koustuban; Hong, Kyung-Han; Wong, Liang Jie; Keathley, Phillip D; Fallahi, A; Zapata, Luis; Kärtner, Franz X

2014-01-01T23:59:59.000Z

326

A surface ionization source  

E-Print Network [OSTI]

The main part of the work described herein is the development and testing of a surface ionization source for use on a collinear fast beam laser spectroscopy apparatus. A description of the previously existing fast beam apparatus is given...

Buzatu, Daniel J.

1995-01-01T23:59:59.000Z

327

National Synchrotron Light Source  

ScienceCinema (OSTI)

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

None

2010-01-08T23:59:59.000Z

328

Galactic Superluminal Sources  

E-Print Network [OSTI]

A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the galactic sources GRS 1915+105 and GRO J1655-40. Both of these objects have given us a broader view of black holes and the formation of jets, yet they also show the complexity of the accretion environment near relativistic objects. The fast apparent motion of the jets, their luminosity and variability, their high energy spectrum, and approximate scaling to the behavior of active galactic nuclei, certainly warrant the description "microquasar". I present a review of the observational data on these sources, and discuss where we stand on a physical picture of GRS 1915+105 and GRO J1655-40 as taken from multi-wavelength studies. I also point out other galactic sources which share some of the properties of the microquasars, and what to look for as a high energy "signature" in future observations.

B. A. Harmon

1998-12-21T23:59:59.000Z

329

ION SOURCES FOR CYCLOTRONS  

E-Print Network [OSTI]

These utilize lasers, plasma focus, sparks, and ex­ plodingextractor voltage A plasma focus device has been used byf n a s Fig. 22: The plasma focus high charge state source

Clark, D.J.

2010-01-01T23:59:59.000Z

330

Computerized Energy Information Sources  

E-Print Network [OSTI]

Many computerized files of energy- and energy conservation-related information are currently available through commercial and governmental sources such as Lockheed Information Systems, System Development Corporation, and DOE/RECON. Private...

Gordon, D.

1979-01-01T23:59:59.000Z

331

Nonponderomotive electron acceleration in ultrashort surface-plasmon fields  

SciTech Connect (OSTI)

We investigate the nonponderomotive nature of ultrafast plasmonic electron acceleration in strongly decaying electromagnetic fields generated by few-cycle and single-cycle femtosecond laser pulses. We clearly identify the conditions contributing to nonponderomotive acceleration and establish fundamental scaling laws and carrier-envelope phase effects. These all-optically accelerated compact, femtosecond electron sources can be utilized in contemporary ultrafast methods.

Racz, Peter; Dombi, Peter [Wigner Research Centre for Physics, Konkoly-Thege M. ut 29-33, H-1121 Budapest (Hungary)

2011-12-15T23:59:59.000Z

332

National Synchrotron Light Source  

ScienceCinema (OSTI)

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

BNL

2009-09-01T23:59:59.000Z

333

Magnetron sputtering source  

DOE Patents [OSTI]

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

Makowiecki, Daniel M. (Livermore, WA); McKernan, Mark A. (Livermore, CA); Grabner, R. Fred (Brentwood, CA); Ramsey, Philip B. (Livermore, CA)

1994-01-01T23:59:59.000Z

334

Magnetron sputtering source  

DOE Patents [OSTI]

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

1994-08-02T23:59:59.000Z

335

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOE Patents [OSTI]

Disclosed is an illumination source comprising a porous silicon having a source of electrons on the surface and/or interstices thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon. 1 fig.

Tam, S.W.

1997-02-25T23:59:59.000Z

336

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOE Patents [OSTI]

An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

Tam, Shiu-Wing (Downers Grove, IL)

1997-01-01T23:59:59.000Z

337

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOE Patents [OSTI]

An illumination source comprising a porous silicon having a source of electrons on the surface and/or interticies thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon.

Tam, Shiu-Wing (Downers Grove, IL)

1998-01-01T23:59:59.000Z

338

Porous silicon with embedded tritium as a stand-alone prime power source for optoelectronic applications  

DOE Patents [OSTI]

An illumination source is disclosed comprising a porous silicon having a source of electrons on the surface and/or interstices thereof having a total porosity in the range of from about 50 v/o to about 90 v/o. Also disclosed are a tritiated porous silicon and a photovoltaic device and an illumination source of tritiated porous silicon. 1 fig.

Tam, S.W.

1998-06-16T23:59:59.000Z

339

Pulsed ion beam source  

DOE Patents [OSTI]

An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

Greenly, J.B.

1997-08-12T23:59:59.000Z

340

COMPACT, TUNABLE COMPTON SCATTERING GAMMA-RAY SOURCES  

SciTech Connect (OSTI)

Recent progress in accelerator physics and laser technology have enabled the development of a new class of gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development at LLNL. High-brightness, relativistic electron bunches produced by the linac interact with a Joule-class, 10 ps laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. The source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented.

Hartemann, F V; Albert, F; Anderson, G G; Anderson, S G; Bayramian, A J; Betts, S M; Chu, T S; Cross, R R; Ebbers, C A; Fisher, S E; Gibson, D J; Ladran, A S; Marsh, R A; Messerly, M J; O'Neill, K L; Semenov, V A; Shverdin, M Y; Siders, C W; McNabb, D P; Barty, C J; Vlieks, A E; Jongewaard, E N; Tantawi, S G; Raubenheimer, T O

2009-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Matter & Energy Electronics  

E-Print Network [OSTI]

See also: Matter & Energy Electronics· Detectors· Technology· Construction· Sports Science Electronic Tongue Tastes Wine Variety, Vintage (Aug. 12, 2008) -- You don't need a wine expert to Advance

Suslick, Kenneth S.

342

Catalac free electron laser  

DOE Patents [OSTI]

A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

343

Development of a hydraulic borehole seismic source  

SciTech Connect (OSTI)

This report describes a 5 year, $10 million Sandia/Industry project to develop an advanced borehole seismic source for use in oil and gas exploration and production. The development Team included Sandia, Chevron, Amoco, Conoco, Exxon, Raytheon, Pelton, and GRI. The seismic source that was developed is a vertically oriented, axial point force, swept frequency, clamped, reaction-mass vibrator design. It was based on an early Chevron prototype, but the new tool incorporates a number of improvements which make it far superior to the original prototype. The system consists of surface control electronics, a special heavy duty fiber optic wireline and draw works, a cablehead, hydraulic motor/pump module, electronics module, clamp, and axial vibrator module. The tool has a peak output of 7,000 lbs force and a useful frequency range of 5 to 800 Hz. It can operate in fluid filled wells with 5.5-inch or larger casing to depths of 20,000 ft and operating temperatures of 170 C. The tool includes fiber optic telemetry, force and phase control, provisions to add seismic receiver arrays below the source for single well imaging, and provisions for adding other vibrator modules to the tool in the future. The project yielded four important deliverables: a complete advanced borehole seismic source system with all associated field equipment; field demonstration surveys funded by industry showing the utility of the system; industrial sources for all of the hardware; and a new service company set up by their industrial partner to provide commercial surveys.

Cutler, R.P.

1998-04-01T23:59:59.000Z

344

Neutrinos in the Electron  

E-Print Network [OSTI]

We will show that one half of the rest mass of the electron is equal to the sum of the rest masses of electron neutrinos and that the other half of the rest mass of the electron is given by the energy in the sum of electric oscillations. With this composition we can explain the rest mass, the electric charge, the spin and the magnetic moment of the electron.

E. L. Koschmieder

2006-09-26T23:59:59.000Z

345

Dual source heat pump  

DOE Patents [OSTI]

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

1982-01-01T23:59:59.000Z

346

INEEL Source Water Assessment  

SciTech Connect (OSTI)

The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 mi2 and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL’s drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey’s Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency’s Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a thick vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL’s Source Water Assessment. Of the INEEL’s 12 public water systems, three systems rated as low susceptibility (EBR-I, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will protect the INEEL’s public water systems yet not too conservative to inhibit the INEEL from carrying out its missions.

Sehlke, Gerald

2003-03-01T23:59:59.000Z

347

Energy Storage & Power Electronics 2008 Peer Review - Power Electronic...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Power Electronics (PE) Systems Presentations Energy Storage & Power Electronics 2008 Peer Review - Power Electronics (PE) Systems Presentations The 2008 Peer Review Meeting for the...

348

COMBUSTION SOURCES OF NITROGEN COMPOUNDS  

E-Print Network [OSTI]

Rasmussen, R.A. (1976). Combustion as a source of nitrousx control for stationary combustion sources. Prog. Energy,CA, March 3-4, 1977 COMBUSTION SOURCES OF NITROGEN COMPOUNDS

Brown, Nancy J.

2011-01-01T23:59:59.000Z

349

Dark Energy and Electrons  

E-Print Network [OSTI]

In the light of recent developments in Dark Energy, we consider the electron in a such a background field and show that at the Compton wavelength the electron is stable, in that the Cassini inward pressure exactly counterbalances the outward Coulomb repulsive pressure thus answering a problem of the earlier electron theory.

Burra G. Sidharth

2008-08-05T23:59:59.000Z

350

OLED area illumination source  

DOE Patents [OSTI]

The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

Foust, Donald Franklin (Scotia, NY); Duggal, Anil Raj (Niskayuna, NY); Shiang, Joseph John (Niskayuna, NY); Nealon, William Francis (Gloversville, NY); Bortscheller, Jacob Charles (Clifton Park, NY)

2008-03-25T23:59:59.000Z

351

Ion source with improved primary arc collimation  

DOE Patents [OSTI]

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Dagenhart, W.K.

1983-12-16T23:59:59.000Z

352

Ion source with improved primary arc collimation  

DOE Patents [OSTI]

An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

Dagenhart, William K. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

353

JLAB Electron Driver Capabilities  

SciTech Connect (OSTI)

Several schemes have been proposed for adding a positron beam option at the Continuous Electron Beam Facility (CEBAF) at Jefferson Laboratory (JLAB). They involve using a primary beam of electrons or gamma rays striking a target to produce a positron beam. At JLAB electron beams are produced and used in two different accelerators, CEBAF and the JLAB FEL (Free Electron Laser). Both have low emittance and energy spread. The CEBAF beam is polarized. The FEL beam is unpolarized but the injector can produce a higher current electron beam. In this paper we describe the characteristics of these beams and the parameters relevant for positron production.

Kazimi, Reza [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2009-09-02T23:59:59.000Z

354

Sealed Radioactive Source Accountability  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To establish Department of Energy (DOE) interim policy and to provide guidance for sealed radioactive source accountability. The directive does not cancel any directives. Extended by DOE N 5400.10 to 12-24-93 & Extended by DOE N 5400.12 to 12-24-94.

1991-12-24T23:59:59.000Z

355

Sealed Radioactive Source Accountability  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

This Notice extends DOE N 5400.9, Sealed Radioactive Source Accountability, of 12-24-91, until 12-24-95, unless sooner superseded or rescinded. The contents of DOE N 5400.9 will be updated and incorporated in the revised DOE O 5480.11, Radiation Protection for Occupational Workers.

1994-12-22T23:59:59.000Z

356

Energy Recovery Linacs for Light Source Applications  

SciTech Connect (OSTI)

Energy Recovery Linacs are being considered for applications in present and future light sources. ERLs take advantage of the continuous operation of superconducting rf cavities to accelerate high average current beams with low losses. The electrons can be directed through bends, undulators, and wigglers for high brightness x ray production. They are then decelerated to low energy, recovering power so as to minimize the required rf drive and electrical draw. When this approach is coupled with advanced continuous wave injectors, very high power, ultra-short electron pulse trains of very high brightness can be achieved. This paper will review the status of worldwide programs and discuss the technology challenges to provide such beams for photon production.

George Neil

2011-04-01T23:59:59.000Z

357

Transmission-mode imaging in the environmental scanning electron microscope (ESEM)  

E-Print Network [OSTI]

sources function by heating a material until it starts to emit electrons (by increasing the energy of free electrons to above the Fermi surface of the material) and field-emission sources function by applying an electric field strong enough that electrons... obtained from studying E. coli, C. necator, and S. Typhimurium (Chapter 8) have been accepted for publication in Scanning, titled “The application of STEM and in-situ controlled dehydration to bac- terial systems using ESEM”. i Acknowledgements This project...

Staniewicz, Lech Thomas Leif

2012-02-07T23:59:59.000Z

358

Betatron radiation based measurement of the electron-beam size in a wakefield accelerator  

SciTech Connect (OSTI)

We present a spatial and spectral characterization of a laser-plasma based betatron source which allows us to determine the betatron oscillation amplitude of the electrons which decreases with increasing electron energies. Due to the observed oscillation amplitude and the independently measured x-ray source size of (1.8{+-}0.3){mu}m we are able to estimate the electron bunch diameter to be (1.6{+-}0.3){mu}m.

Schnell, Michael; Saevert, Alexander; Reuter, Maria [Institut fuer Optik und Quantenelektronik, Friedrich- Schiller- Universitaet, Jena (Germany); and others

2012-07-09T23:59:59.000Z

359

Published in IET Power Electronics Received on 24th April 2012  

E-Print Network [OSTI]

@gmail.com Abstract: Power electronic converters are essential part of hybrid fuel cell automotive application systemsPublished in IET Power Electronics Received on 24th April 2012 Revised on 23rd October 2012 the FC output voltage without using extra power electronic devices by using a Z-source inverter [15, 16

Simões, Marcelo Godoy

360

THE POWER SUPPLY SYSTEM FOR THE ACCELERATING COLUMN OF THE 2 MEV ELECTRON COOLER FOR COSY  

E-Print Network [OSTI]

a high-energy electron beam. The power supply for the accelerating column of the electron cooling systemTHE POWER SUPPLY SYSTEM FOR THE ACCELERATING COLUMN OF THE 2 MEV ELECTRON COOLER FOR COSY D controlled voltage source for 60 kV, 1mA and an additional supply for the solenoids of the magnetic system

Kozak, Victor R.

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Polarized electron beams at milliampere average current  

SciTech Connect (OSTI)

This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

Poelker, Matthew [JLAB

2013-11-01T23:59:59.000Z

362

Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate  

SciTech Connect (OSTI)

We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States)] [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)] [Laboratoire d'Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

2013-02-11T23:59:59.000Z

363

Calibrated vapor generator source  

DOE Patents [OSTI]

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

1995-09-26T23:59:59.000Z

364

Voltage controlled current source  

DOE Patents [OSTI]

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

365

Evaluated teletherapy source library  

DOE Patents [OSTI]

The Evaluated Teletherapy Source Library (ETSL) is a system of hardware and software that provides for maintenance of a library of useful phase space descriptions (PSDs) of teletherapy sources used in radiation therapy for cancer treatment. The PSDs are designed to be used by PEREGRINE, the all-particle Monte Carlo dose calculation system. ETSL also stores other relevant information such as monitor unit factors (MUFs) for use with the PSDs, results of PEREGRINE calculations using the PSDs, clinical calibration measurements, and geometry descriptions sufficient for calculational purposes. Not all of this information is directly needed by PEREGRINE. It also is capable of acting as a repository for the Monte Carlo simulation history files from which the generic PSDs are derived.

Cox, Lawrence J. (Los Alamos, NM); Schach Von Wittenau, Alexis E. (Livermore, CA)

2000-01-01T23:59:59.000Z

366

Science and Technology of Future Light Sources  

SciTech Connect (OSTI)

Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects. The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee [1]. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons. and spins, as illustrated in Figure 1.1, and serve the entire range of science from advanced materials to life sciences. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. X-rays with energies above 10 keV offer capabilities extending beyond the nanoworld shown in Figure 1.1 due to their ability to penetrate into optically opaque or thick objects. This opens the door to combining atomic level information from scattering studies with 3D information on longer length scales from real space imaging with a resolution approaching 1 nm. The investigation of multiple length scales is important in hierarchical structures, providing knowledge about function of living organisms, the atomistic origin of materials failure, the optimization of industrial synthesis, or the working of devices. Since the fundamental interaction that holds matter together is of electromagnetic origin, it is intuitively clear that electromagnetic radiation is the critical tool in the study of material properties. On the level of atoms, electrons, and spins, x-rays have proved especially valuable. Future advanced x-ray sources and instrumentation will extend the power of x-ray methods to reach greater spatial resolution, increased sensitivity, and unexplored temporal domains. The purpose of this document is threefold: (1) summarize scientific opportunities that are beyond the reach of today's x-ray sources and instrumentation; (2) summarize the requirements for advanced x-ray sources and instrumentation needed to realize these scientific opportunities, as well as potential methods of achieving them; and (3) outline the R&D required to establish the technical feasibility of these advanced x-ray sources and instrumentation.

Dierker,S.; Bergmann, U.; Corlett, J.; Dierker, S.; Falcone, R.; Galayda, J.; Gibson, M.; Hastings, J.; Hettel, B.; Hill, J.; Hussain, Z.; Kao, C.-C.; Kirx, J.; Long, G.; McCurdy, B.; Raubenheimer, T.; Sannibale, F.; Seeman, J.; Shen, Z.-X.; Shenoy, g.; Schoenlein, B.; Shen, Q.; Stephenson, B.; Stohr, J.; Zholents, A.

2008-12-01T23:59:59.000Z

367

Science and Technology of Future Light Sources  

SciTech Connect (OSTI)

Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee [1]. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons. and spins, as illustrated in Figure 1.1, and serve the entire range of science from advanced materials to life sciences. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. X-rays with energies above 10 keV offer capabilities extending beyond the nanoworld shown in Figure 1.1 due to their ability to penetrate into optically opaque or thick objects. This opens the door to combining atomic level information from scattering studies with 3D information on longer length scales from real space imaging with a resolution approaching 1 nm. The investigation of multiple length scales is important in hierarchical structures, providing knowledge about function of living organisms, the atomistic origin of materials failure, the optimization of industrial synthesis, or the working of devices. Since the fundamental interaction that holds matter together is of electromagnetic origin, it is intuitively clear that electromagnetic radiation is the critical tool in the study of material properties. On the level of atoms, electrons, and spins, x-rays have proved especially valuable. Future advanced x-ray sources and instrumentation will extend the power of x-ray methods to reach greater spatial resolution, increased sensitivity, and unexplored temporal domains. The purpose of this document is threefold: (1) summarize scientific opportunities that are beyond the reach of today's x-ray sources and instrumentation; (2) summarize the requirements for advanced x-ray sources and instrumentation needed to realize these scientific opportunities, as well as potential methods of achieving them; and (3) outline the R&D required to establish the technical feasibility of these advanced x-ray sources and instrumentation.

Bergmann, Uwe; Corlett, John; Dierker, Steve; Falcone, Roger; Galayda, John; Gibson, Murray; Hastings, Jerry; Hettel, Bob; Hill, John; Hussain, Zahid; Kao, Chi-Chang; Kirz, Janos; Long, Danielle; McCurdy, Bill; Raubenheimer, Tor; Sannibale, Fernando; Seeman, John; Shen, Z.-X.; Schenoy, Gopal; Schoenlein, Bob; Shen, Qun; Stephenson, Brian; St& #246; hr, Joachim; Zholents, Alexander

2009-01-28T23:59:59.000Z

368

The European Spallation Source  

SciTech Connect (OSTI)

The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.

2011-03-01T23:59:59.000Z

369

Capillary discharge source  

DOE Patents [OSTI]

Debris generation from an EUV electric discharge plasma source device can be significantly reduced or essentially eliminated by encasing the electrodes with dielectric or electrically insulating material so that the electrodes are shielded from the plasma, and additionally by providing a path for the radiation to exit wherein the electrodes are not exposed to the area where the radiation is collected. The device includes: (a) a body, which is made of an electrically insulating material, that defines a capillary bore that has a proximal end and a distal end and that defines at least one radiation exit; (b) a first electrode that defines a first channel that has a first inlet end that is connected to a source of gas and a first outlet end that is in communication with the capillary bore, wherein the first electrode is positioned at the distal end of the capillary bore; (c) a second electrode that defines a second channel that has a second inlet end that is in communication with the capillary bore and an outlet end, wherein the second electrode is positioned at the proximal end of the capillary bore; and (d) a source of electric potential that is connected across the first and second electrodes, wherein radiation generated within the capillary bore is emitted through the at least one radiation exit and wherein the first electrode and second electrode are shielded from the emitted radiation.

Bender, III, Howard Albert

2003-11-25T23:59:59.000Z

370

Acceleration of electrons using an inverse free electron laser auto- accelerator  

SciTech Connect (OSTI)

We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW's) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.

Wernick, I.K.; Marshall, T.C.

1992-07-01T23:59:59.000Z

371

Acceleration of electrons using an inverse free electron laser auto- accelerator  

SciTech Connect (OSTI)

We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW`s) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.

Wernick, I.K.; Marshall, T.C.

1992-07-01T23:59:59.000Z

372

Self-contained hot-hollow cathode gun source assembly  

DOE Patents [OSTI]

A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

Zeren, Joseph D. (Boulder, CO)

1986-01-01T23:59:59.000Z

373

Test of potential homogeneity in the KATRIN gaseous tritium source  

E-Print Network [OSTI]

83mKr is supposed to be used to study the properties of the windowless gaseous tritium source of the experiment KATRIN. In this work we deduce the amount of 83mKr which is necessary to determine possible potential inhomogeneities via conversion-electron-line broadening.

M. Rysavy

2005-06-02T23:59:59.000Z

374

Self-contained hot-hollow cathode gun source assembly  

DOE Patents [OSTI]

A self-contained hot-hollow cathode gun source assembly for use in a vacuum chamber includes a crucible block having a hot-hollow cathode gun mounted underneath and providing a hole for the magnetic deflection of the ion/electron beam into a crucible on top the block.

Zeren, J.D.

1984-08-01T23:59:59.000Z

375

National Synchrotron Light Source II Project Progress Report  

E-Print Network [OSTI]

Upton, New York 11973 #12;NSLS-II PROJECT DIRECTOR'S ASSESSMENT MAY 2010 OVERALL ASSESSMENT The National Synchrotron Light Source II project maintained excellent technical progress and satisfactory cost and schedule, power supplies, and electronics is making excellent progress. The preliminary designs of the six project

Ohta, Shigemi

376

Proceedings of the 10th international workshop on ECR ion sources  

SciTech Connect (OSTI)

This report contains papers on the following topics: Recent Developments and Future Projects on ECR Ion Sources; Operation of the New KVI ECR Ion Source at 10 GHz; Operational Experience and Status of the INS SF-ECR Ion Source; Results of the New ECR4'' 14.5 GHz ECRIS; Preliminary Performance of the AECR; Experimental Study of the Parallel and Perpendicular Particle Losses from an ECRIS Plasma; Plasma Instability in Electron Cyclotron Resonance Heated Ion Sources; The Hyperbolic Energy Analyzer; Status of ECR Source Development; The New 10 GHz CAPRICE Source; First Operation of the Texas A M ECR Ion Source; Recent Developments of the RIKEN ECR Ion Sources; The 14 GHz CAPRICE Source; Characteristics and Potential Applications of an ORNL Microwave ECR Multicusp Plasma Ion Source; ECRIPAC: The Production and Acceleration of Multiply Charged Ions Using an ECR Plasma; ECR Source for the HHIRF Tandem Accelerator; Feasibility Studies for an ECR-Generated Plasma Stripper; Production of Ion Beams by using the ECR Plasmas Cathode; A Single Stage ECR Source for Efficient Production of Radioactive Ion Beams; The Single Staged ECR Source at the TRIUMF Isotope Separator TISOL; The Continuous Wave, Optically Pumped H{sup {minus}} Source; The H{sup +} ECR Source for the LAMPF Optically Pumped Polarized Ion Source; Present Status of the Warsaw CUSP ECR Ion Source; An ECR Source for Negative Ion Production; GYRAC-D: A Device for a 200 keV ECR Plasma Production and Accumulation; Status Report of the 14.4 GHZ ECR in Legnaro; Status of JYFL-ECRIS; Report on the Uppsala ECRIS Facility and Its Planned Use for Atomic Physics; A 10 GHz ECR Ion Source for Ion-Electron and Ion-Atom Collision Studies; and Status of the ORNL ECR Source Facility for Multicharged Ion Collision Research.

Meyer, F W; Kirkpatrick, M I [eds.

1991-01-01T23:59:59.000Z

377

Compact Gamma-ray Source Technology Development Study  

SciTech Connect (OSTI)

This study focuses on the applicability of current accelerator and laser technologies to the construction of compact, narrow bandwidth, gamma-ray sources for DHS missions in illicit materials detection. It also identifies research and development areas in which advancement will directly benefit these light sources. In particular, we review the physics of Compton scattering based light sources and emphasize the source properties most important to Nuclear Resonance Fluorescence (NRF) applications of interest. The influences of laser and electron beam properties on the light source are examined in order to evaluate the utility of different technologies for this application. Applicable bulk and fiber-based laser systems and laser recirculation technologies are discussed and Radio Frequency (RF) Linear Accelerator (linac) technologies are examined to determine the optimal frequency and pulse formats achievable.

Anderson, S G; Gibson, D J; Rusnak, B

2009-09-25T23:59:59.000Z

378

Ceramic Electron Multiplier  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

Comby, G.

1996-10-01T23:59:59.000Z

379

Environment assisted electron capture  

E-Print Network [OSTI]

Electron capture by {\\it isolated} atoms and ions proceeds by photorecombination. In this process a species captures a free electron by emitting a photon which carries away the excess energy. It is shown here that in the presence of an {\\it environment} a competing non-radiative electron capture process can take place due to long range electron correlation. In this interatomic (intermolecular) process the excess energy is transferred to neighboring species. The asymptotic expression for the cross section of this process is derived. We demonstrate by explicit examples that under realizable conditions the cross section of this interatomic process can clearly dominate that of photorecombination.

Kirill Gokhberg; Lorenz S. Cederbaum

2009-11-09T23:59:59.000Z

380

Radiological Electron Microprobe | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

from the Hanford Site provide complementary data to ongoing activities in EMSL's microfluidics and Subsurface Flow and Transport capabilities. User Portal Name: Electron...

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Photon Source Parameters  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter |Photoinduced electronPhoton

382

Photon Source Parameters  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter |Photoinduced electronPhotonPhoton

383

Reversible electron beam heating for suppression of microbunching instabilities at free-electron lasers  

E-Print Network [OSTI]

The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future X-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., "heating" the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) in front and behind a magnetic bunch compressor chicane. The additional energy spread will be introduced in the first TDS, which suppresses the microbunching instability, and then will be eliminated in the second T...

Behrens, Christopher; Xiang, Dao

2011-01-01T23:59:59.000Z

384

Cosmic-ray electron signatures of dark matter  

SciTech Connect (OSTI)

There is evidence for an excess in cosmic-ray electrons at about 500 GeV energy, that may be related to dark-matter annihilation. I have calculated the expected electron contributions from a pulsar and from Kaluza-Klein dark matter, based on a realistic treatment of the electron propagation in the Galaxy. Pulsars younger than about 10{sup 5} years naturally cause a narrow peak at a few hundred GeV in the locally observed electron spectrum, similar to that observed. On the other hand, if electron production by dark matter is predominantly occurring in high-mass clumps (> or approx. 10{sup 3}M{sub {center_dot}}), the sharp cutoff in the contribution from Kaluza-Klein particles is sometimes more pronounced, but often smoothed out and indistinguishable from a pulsar source, and therefore the spectral shape of the electron excess is insufficient to discriminate a dark-matter origin from more conventional astrophysical explanations.

Pohl, Martin [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

2009-02-15T23:59:59.000Z

385

Electron beam directed energy device and methods of using same  

DOE Patents [OSTI]

A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

Retsky, Michael W. (Trumbull, CT)

2007-10-16T23:59:59.000Z

386

Compact ion accelerator source  

DOE Patents [OSTI]

An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

2014-04-29T23:59:59.000Z

387

The European Spallation Source  

SciTech Connect (OSTI)

In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

2011-04-20T23:59:59.000Z

388

Photon Source Parameters  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheStevenAdministrationPhotometric Variations asPhoton Source

389

Source Selection Guide  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment of Energy U.S.Improve Emitter Efficiency Under High-Current Operation Source

390

Source Selection Guide  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment of Energy U.S.Improve Emitter Efficiency Under High-Current Operation Source

391

SOURCE SELECTION INFORMATION -  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGY TAXBalancedDepartmentRestrictions onSBBiodiesel | DepartmentSLACofof98-02|10,SOURCE

392

Sources of tritium  

SciTech Connect (OSTI)

A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

Phillips, J.E.; Easterly, C.E.

1980-12-01T23:59:59.000Z

393

Invited Article: Characterization of background sources in space-based time-of-flight mass spectrometers  

SciTech Connect (OSTI)

For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward St, Ann Arbor, Michigan 48109 (United States); Orlando, T. M.; McLain, J. [Georgia Institute of Technology, 225 North Ave NW, Atlanta, Georgia 30332 (United States); Steiger, R. von [International Space Science Institute, Hallerstrasse 6, CH-3012 Bern, Switzerland and Physikalisches Institut, Universität Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

2014-09-15T23:59:59.000Z

394

Electronic Mail Analysis Capability  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

Establishes the pilot program to test the Department of Energy (DOE) Electronic Mail Analysis Capability (EMAC), which will be used to monitor and analyze outgoing and incoming electronic mail (e-mail) from the National Nuclear Security Administration (NNSA) and DOE laboratories that are engaged in nuclear weapons design or work involving special nuclear material. No cancellation.

2001-01-08T23:59:59.000Z

395

Federal Funding Sources of Information Sources for Automatic Funding Notices  

E-Print Network [OSTI]

;Federal Funding Sources of Information r Grant Programs & Deadlines q World Health Organization - GrantFederal Funding Sources of Information Sources for Automatic Funding Notices q Catalogue of Federal Domestic Assistance q Grants.Gov q FedBizOpps q The Foundation Center r RFP Bulletin r Philanthropy News

396

Electrons and Mirror Symmetry  

SciTech Connect (OSTI)

The neutral weak force between an electron and a target particle, mediated by the Z boson, can be isolated by measuring the fractional change under a mirror reflection of the scattering probability of relativistic longitudinally polarized electrons off unpolarized targets. This technique yields neutral weak force measurements at a length scale of 1 femtometer, in contrast to high energy collider measurements that probe much smaller length scales. Study of the variation of the weak force over a range of length scales provides a stringent test of theory, complementing collider measurements. We describe a recent measurement of the neutral weak force between two electrons by the E158 experiment at the Stanford Linear Accelerator Center. While the weak force between an electron and positron has been extensively studied, that between two electrons had never directly been measured. We conclude by discussing prospects for even more precise measurements at future facilities.

Kumar, Krishna (University of Massachusetts, Amherst) [University of Massachusetts, Amherst

2007-04-04T23:59:59.000Z

397

A Dipole Assisted IEC Neutron Source  

SciTech Connect (OSTI)

A potential opportunity to enhance Inertial Electrostatic Confinement (IEC) fusion exists by augmenting it with a magnetic dipole configuration. The theory is that the dipole fields will enhance the plasma density in the center region of the IEC and the combined IEC and dipole confinement properties will reduce plasma losses. To demonstrate that a hybrid Dipole-IEC configuration can provide an improved neutron source vs. a stand alone IEC, a first model Dipole-IEC experiment was benchmarked against a reference IEC. A triple Langmuir probe was used to find the electron temperature and density. It was found that the magnetic field increases the electron density by a factor of 16, the electron temperature decreases in the presence of a magnetic field, the discharge voltage decreases in the presence of a magnetic field, the potential of the dipole strongly influences the densities obtained in the center. The experimental set-up and plasma diagnostics are discussed in detail, as well as the results, and the developmental issues.

Prajakti Joshi Shrestha

2005-11-28T23:59:59.000Z

398

Advanced Photon Source Upgrade Project  

ScienceCinema (OSTI)

Upgrade to Advanced Photon Source announced by Department Of Energy. Read more: http://go.usa.gov/ivZ

Mitchell, John; Gibson, Murray; Young, Linda; Joachimiak, Andrzej

2013-04-19T23:59:59.000Z

399

Physics design of a cold neutron source for KIPT neutron source facility.  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of a neutron source facility. It is based on the use of an electron accelerator driven subcritical (ADS) facility with low enriched uranium fuel, using the existing electron accelerators at KIPT of Ukraine [1]. The neutron source of the subcritical assembly is generated from the interaction of 100-KW electron beam, which has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, with a natural uranium target [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron beam experiments and material studies are also included. Over the past two-three decades, structures with characteristic lengths of 100 {angstrom} and correspondingly smaller vibrational energies have become increasingly important for both science and technology [3]. The characteristic dimensions of the microstructures can be well matched by neutrons with longer vibrational wavelength and lower energy. In the accelerator-driven subcritical facility, most of the neutrons are generated from fission reactions with energy in the MeV range. They are slowed down to the meV energy range through scattering reactions in the moderator and reflector materials. However, the fraction of neutrons with energies less than 5 meV in a normal moderator spectrum is very low because of up-scattering caused by the thermal motion of moderator or reflector molecules. In order to obtain neutrons with energy less than 5 meV, cryogenically cooled moderators 'cold neutron sources' should be used to slow down the neutrons. These cold moderators shift the neutron energy spectrum down because the thermal motion of moderator molecules as well as the up-scattering is very small, which provides large gains in intensity of low energy neutrons, E < 5 meV. The accelerator driven subcritical facility is designed with a provision to add a cryogenically cooled moderator system. This cold neutron source could provide the neutrons beams with lower energy, which could be utilized in scattering experiment and material structures analysis. This study describes the performed physics analyses to define and characterize the cold neutron source of the KIPT neutron source facility. The cold neutron source is designed to optimize the cold neutron brightness to the experimental instruments outside the radial heavy concrete shield of the facility. Liquid hydrogen or solid methane with 20 K temperature is used as a cold moderator. Monte Carlo computer code MCNPX [4], with ENDF/B-VI nuclear data libraries, is utilized to calculate the cold neutron source performance and estimate the nuclear heat load to the cold moderator. The surface source generation capability of MCNPX code has been used to provide the possibility of analyzing different design configurations and perform design optimization analyses with reasonable computer resources. Several design configurations were analyzed and their performance were characterized and optimized.

Zhong, Z.; Gohar, Y.; Kellogg, R.; Nuclear Engineering Division

2009-02-17T23:59:59.000Z

400

Infrared source test  

SciTech Connect (OSTI)

The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

Ott, L.

1994-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Thulium-170 heat source  

DOE Patents [OSTI]

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

402

Multiple source heat pump  

DOE Patents [OSTI]

A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

403

Aerogels for electronics  

SciTech Connect (OSTI)

In addition to their other exceptional properties, aerogels also exhibit unusual dielectric and electronic properties due to their nano-sized structures and high porosities. For example, aerogels have the lowest dielectric constants measured for a solid material (having values approaching 1.0); they have exceptionally high dielectric resistivities and strengths (i.e., ability to insulate very high voltages); they exhibit low dielectric loss at microwave frequencies; and some aerogels are electrically conductive and photoconductive. These properties are being exploited to provide the next generation of materials for energy storage, low power consumption, and ultra-fast electronics. We are working toward adapting these unusual materials for microelectronic applications, particularly, making thin aerogel films for dielectric substrates and for energy storage devices such as supercapacitors. Measurements are presented in this paper for the dielectric and electronic properties of aerogels, including the dielectric constant, loss factor, dielectric and electrical conductivity, volume resistivity, and dielectric strength. We also describe methods to form and characterize thin aerogel films which are being developed for numerous electronic applications. Finally, some of the electronic applications proposed for aerogels are presented. Commercialization of aerogels for electronics must await further feasibility, prototype development, and cost studies, but they are one of the key materials and are sure to have a major impact on future electronics.

Hrubesh, L.W.

1994-10-01T23:59:59.000Z

404

Design and operation of the electron beam ion trap  

SciTech Connect (OSTI)

This report describes the basic features and operating principles of the Electron Beam Ion Trap. The differences between EBIT and other sources of highly charged ions are outlined. Its features and operating parameters are discussed. The report also explains why certain design choices were necessary and the constraints involved in building an electron beam ion trap. EBIT's evaporation cooling system is described in detail. 13 refs., 8 figs.

Vogel, D.

1990-05-30T23:59:59.000Z

405

Feedback from Clustered Sources During Reionization  

E-Print Network [OSTI]

The reionization history of the intergalactic medium (IGM) at high redshift (z > 6) was likely strongly shaped by several global feedback processes. Because the earliest ionizing sources formed at the locations of the rare density peaks, their spatial distribution was strongly clustered. Here we demonstrate that this clustering significantly boosts the impact of feedback processes operating at high redshift. We build a semi-analytical model to include feedback and clustering simultaneously, and apply this model to the suppression of star-formation in minihalos due to photoionization. The model is built on the excursion-set-based formalism of Furlanetto, Zaldarriaga and Hernquist (2004), which incorporates the clustering of ionizing sources, and which we here extend to include suppression of star formation in minihalos. We find that clustering increases the mean HII bubble size by a factor of several, and it dramatically increases the fraction of minihalos that are suppressed, by a factor of up to 60 relative to a randomly distributed population. This enhanced suppression can significantly reduce the electron scattering optical depth, as required by the three-year data from the Wilkinson Microwave Anisotropy Probe (WMAP). We argue that source clustering is likely to similarly boost the importance of a variety of other feedback mechanisms.

Roban Hultman Kramer; Zoltan Haiman; S. Peng Oh

2006-04-10T23:59:59.000Z

406

X-ray Free-electron Lasers  

SciTech Connect (OSTI)

In a free-electron laser (FEL) the lasing medium is a high-energy beam of electrons flying with relativistic speed through a periodic magnetic field. The interaction between the synchrotron radiation that is produced and the electrons in the beam induces a periodic bunching of the electrons, greatly increasing the intensity of radiation produced at a particular wavelength. Depending only on a phase match between the electron energy and the magnetic period, the wavelength of the FEL radiation can be continuously tuned within a wide spectral range. The FEL concept can be adapted to produce radiation wavelengths from millimeters to Angstroms, and can in principle produce hard x-ray beams with unprecedented peak brightness, exceeding that of the brightest synchrotron source by ten orders of magnitude or more. This paper focuses on short-wavelength FELs. It reviews the physics and characteristic properties of single-pass FELs, as well as current technical developments aiming for fully coherent x-ray radiation pulses with pulse durations in the 100 fs to 100 as range. First experimental results at wavelengths around 100 nm and examples of scientific applications planned on the new, emerging x-ray FEL facilities are presented.

Feldhaus, J.; /DESY; Arthur, J.; Hastings, J.B.; /SLAC

2007-02-23T23:59:59.000Z

407

Technical Report Ultrafast X-ray Science at the Sub-Picosecond Pulse Source  

E-Print Network [OSTI]

1 Technical Report Ultrafast X-ray Science at the Sub-Picosecond Pulse Source Kelly J. Gaffney ultrafast phenomena. These techniques involve excitation of a sample with an ultrafast laser pump pulse, USA The ultrafast, high brightness x-ray free electron laser (XFEL) sources of the future have

Wechsler, Risa H.

408

X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof  

DOE Patents [OSTI]

An x-ray source assembly and method of operation are provided having enhanced output stability. The assembly includes an anode having a source spot upon which electrons impinge and a control system for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

Radley, Ian (Glenmont, NY); Bievenue, Thomas J. (Delmar, NY); Burdett, John H. (Charlton, NY); Gallagher, Brian W. (Guilderland, NY); Shakshober, Stuart M. (Hudson, NY); Chen, Zewu (Schenectady, NY); Moore, Michael D. (Alplaus, NY)

2008-06-08T23:59:59.000Z

409

Helicon wave excitation to produce energetic electrons for manufacturing semiconductors  

DOE Patents [OSTI]

A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18-0.35 mm or less.

Molvik, Arthur W. (Livermore, CA); Ellingboe, Albert R. (Fremont, CA)

1998-01-01T23:59:59.000Z

410

Helicon wave excitation to produce energetic electrons for manufacturing semiconductors  

DOE Patents [OSTI]

A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18--0.35 mm or less. 16 figs.

Molvik, A.W.; Ellingboe, A.R.

1998-10-20T23:59:59.000Z

411

Method for generating a plasma wave to accelerate electrons  

DOE Patents [OSTI]

The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the electron gun system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode triggering system; the electron diagnostics; and the feedback system between the electron diagnostics and the laser system. The system also includes plasma source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the plasma wave, and thus the electron acceleration, using the method of the invention.

Umstadter, Donald (Ann Arbor, MI); Esarey, Eric (Chevy Chase, MD); Kim, Joon K. (Ann Arbor, MI)

1997-01-01T23:59:59.000Z

412

Method for generating a plasma wave to accelerate electrons  

DOE Patents [OSTI]

The invention provides a method and apparatus for generating large amplitude nonlinear plasma waves, driven by an optimized train of independently adjustable, intense laser pulses. In the method, optimal pulse widths, interpulse spacing, and intensity profiles of each pulse are determined for each pulse in a series of pulses. A resonant region of the plasma wave phase space is found where the plasma wave is driven most efficiently by the laser pulses. The accelerator system of the invention comprises several parts: the laser system, with its pulse-shaping subsystem; the electron gun system, also called beam source, which preferably comprises photo cathode electron source and RF-LINAC accelerator; electron photo-cathode triggering system; the electron diagnostics; and the feedback system between the electron diagnostics and the laser system. The system also includes plasma source including vacuum chamber, magnetic lens, and magnetic field means. The laser system produces a train of pulses that has been optimized to maximize the axial electric field amplitude of the plasma wave, and thus the electron acceleration, using the method of the invention. 21 figs.

Umstadter, D.; Esarey, E.; Kim, J.K.

1997-06-10T23:59:59.000Z

413

Accelerator shield design of KIPT neutron source facility  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of a neutron source facility at KIPT utilizing an electron-accelerator-driven subcritical assembly. Electron beam power is 100 kW, using 100 MeV electrons. The facility is designed to perform basic and applied nuclear research, produce medical isotopes, and train young nuclear specialists. The biological shield of the accelerator building is designed to reduce the biological dose to less than 0.5-mrem/hr during operation. The main source of the biological dose is the photons and the neutrons generated by interactions of leaked electrons from the electron gun and accelerator sections with the surrounding concrete and accelerator materials. The Monte Carlo code MCNPX serves as the calculation tool for the shield design, due to its capability to transport electrons, photons, and neutrons coupled problems. The direct photon dose can be tallied by MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is less than 0.01 neutron per electron. This causes difficulties for Monte Carlo analyses and consumes tremendous computation time for tallying with acceptable statistics the neutron dose outside the shield boundary. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were developed for the study. The generated neutrons are banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron and secondary photon doses. The weight windows variance reduction technique is utilized for both neutron and photon dose calculations. Two shielding materials, i.e., heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain the total dose outside the shield boundary at less than 0.5-mrem/hr. The shield configuration and parameters of the accelerator building have been determined and are presented in this paper. (authors)

Zhong, Z.; Gohar, Y. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)

2013-07-01T23:59:59.000Z

414

Electron Microscope Facility  

ScienceCinema (OSTI)

Brookhaven Lab is home to one of only a few Scanning Transmision Electron Microscope (STEM) machines in the world and one of the few that can image single heavy atoms.

None

2010-01-08T23:59:59.000Z

415

VIA ELECTRONIC MAIL  

Energy Savers [EERE]

VIA ELECTRONIC MAIL U.S. Department of Energy (FE-34) Office of Fossil Energy Office of Oil and Gas Global Security and Supply Attn: Natural Gas Reports P.O. Box 44375...

416

Linkping University Electronic Press  

E-Print Network [OSTI]

do so. Beyond Ph.D. theses, 41 Licentiate theses (of 61 in total) were published electronically-Press to 640, 208 and 4794 Ph.D., Licentiate and Undergraduate theses, respectively. Conference Proceedings

Zhao, Yuxiao

417

Toward pure electronic spectroscopy  

E-Print Network [OSTI]

In this thesis is summarized the progress toward completing our understanding of the Rydberg system of CaF and developing Pure Electronic Spectroscopy. The Rydberg system of CaF possesses a paradigmatic character due to ...

Petrovi?, Vladimir, 1978-

2009-01-01T23:59:59.000Z

418

3D Printing Electronics  

E-Print Network [OSTI]

Login Register Home Videos Jobs Games 3D Printing Electronics Design Software Designer Edge for 3D Printing · -- B6 Sigma Labs (ticker SGLB) is not the same company as Sigma Technologies

Stryk, Oskar von

419

electronic reprint Synchrotron  

E-Print Network [OSTI]

electronic reprint Journal of Synchrotron Radiation ISSN 0909-0495 Editor: G. Ice Accurate dose required to produce a defined outcome, following the Grotthuss­Draper law (King & Laidler, 1984

Hitchcock, Adam P.

420

Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun  

SciTech Connect (OSTI)

The objective was to complete the design of an electron gun which utilizes a radio frequency (RF) power source to apply a voltage to a field emission (FE) cathode, a so called cold cathode, in order to produce an electron beam. The concept of the RF electron gun was originally conceived at Argonne National Laboratory but never reduced to practice. The research allowed the completion of the design based upon the integration of the FE electron source. Compared to other electron guns, the RF gun is very compact, less than one third the size of other comparable guns, and produces a high energy (to several MeV), high quality, high power electron beam with a long focal length with high repetition rates. The resultant electron gun may be used in welding, materials processing, analytical equipment and waste treatment.

McGuire, Gary; Martin, Allen; Noonan, John

2010-10-30T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Laser fusion neutron source employing compression with short pulse lasers  

DOE Patents [OSTI]

A method and system for achieving fusion is provided. The method includes providing laser source that generates a laser beam and a target that includes a capsule embedded in the target and filled with DT gas. The laser beam is directed at the target. The laser beam helps create an electron beam within the target. The electron beam heats the capsule, the DT gas, and the area surrounding the capsule. At a certain point equilibrium is reached. At the equilibrium point, the capsule implodes and generates enough pressure on the DT gas to ignite the DT gas and fuse the DT gas nuclei.

Sefcik, Joseph A; Wilks, Scott C

2013-11-05T23:59:59.000Z

422

In-Source Fragmentation and the Sources of Partially Tryptic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

using three biological samples, including a standard protein mixture, a mouse brain tissue homogenate, and a mouse plasma sample. Since the in-source fragments of a...

423

Strong shock generation by fast electron energy deposition  

SciTech Connect (OSTI)

It has been suggested that fast electrons may play a beneficial role in the formation of the ignitor shock in shock ignition owing to the high areal density of the fuel at the time of the ignitor pulse. In this paper, we extend previous studies which have focused on monoenergetic electron sources to populations with extended energy distributions. In good agreement with analytic scalings, we show that strong shocks can be produced with peak pressures of a few hundred Mbar to over 1 Gbar using fast electron intensities of 1–10 PW/cm{sup 2} in a uniform deuterium-tritium plasma at 10 g/cm{sup 3}. However, the length required for shock formation increases with fast electron temperature. As this shock formation distance becomes comparable to the target size, the shock is not able to fully develop, and this implies a limit on the ability of fast electrons to aid shock formation.

Fox, T. E.; Pasley, J. [York Plasma Institute, University of York, York YO10 5DD (United Kingdom) [York Plasma Institute, University of York, York YO10 5DD (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Robinson, A. P. L. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)] [Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom)

2013-12-15T23:59:59.000Z

424

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC  

SciTech Connect (OSTI)

to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B.; Toth, C.

2009-05-04T23:59:59.000Z

425

Electron Heating in a Relativistic, Weibel-Unstable Plasma  

E-Print Network [OSTI]

The dynamics of two initially unmagnetized relativistic counter-streaming homogeneous ion-electron plasma beams are simulated in two dimensions using the particle-in-cell (PIC) method. It is shown that current filaments, which form due to the Weibel instability, develop a large scale longitudinal electric field in the direction opposite to the current carried by the filaments as predicted by theory. Fast moving ions in the current filaments decelerate due to this longitudinal electric field. The same longitudinal electric field, which is partially inductive and partially electrostatic, is identified as the main source of acceleration of electrons in the current filaments. The transverse electric field, though larger than the longitudinal one, is shown to play a smaller role in heating electrons, contrary to previous claims. It is found that, in 1D, the electrons become strongly magnetized and are \\textit{not} accelerated beyond their initial kinetic energy. Rather, the heating of the electrons is enhanced by ...

Kumar, Rahul; Gedalin, Michael

2015-01-01T23:59:59.000Z

426

KAPPA DISTRIBUTION MODEL FOR HARD X-RAY CORONAL SOURCES OF SOLAR FLARES  

SciTech Connect (OSTI)

Solar flares produce hard X-ray emission, the photon spectrum of which is often represented by a combination of thermal and power-law distributions. However, the estimates of the number and total energy of non-thermal electrons are sensitive to the determination of the power-law cutoff energy. Here, we revisit an 'above-the-loop' coronal source observed by RHESSI on 2007 December 31 and show that a kappa distribution model can also be used to fit its spectrum. Because the kappa distribution has a Maxwellian-like core in addition to a high-energy power-law tail, the emission measure and temperature of the instantaneous electrons can be derived without assuming the cutoff energy. Moreover, the non-thermal fractions of electron number/energy densities can be uniquely estimated because they are functions of only the power-law index. With the kappa distribution model, we estimated that the total electron density of the coronal source region was {approx}2.4 Multiplication-Sign 10{sup 10} cm{sup -3}. We also estimated without assuming the source volume that a moderate fraction ({approx}20%) of electrons in the source region was non-thermal and carried {approx}52% of the total electron energy. The temperature was 28 MK, and the power-law index {delta} of the electron density distribution was -4.3. These results are compared to the conventional power-law models with and without a thermal core component.

Oka, M.; Ishikawa, S.; Saint-Hilaire, P.; Krucker, S.; Lin, R. P. [Space Sciences Laboratory, University of California Berkeley (United States)] [Space Sciences Laboratory, University of California Berkeley (United States)

2013-02-10T23:59:59.000Z

427

Miniature quadrupole mass spectrometer having a cold cathode ionization source  

DOE Patents [OSTI]

An improved quadrupole mass spectrometer is described. The improvement lies in the substitution of the conventional hot filament electron source with a cold cathode field emitter array which in turn allows operating a small QMS at much high internal pressures then are currently achievable. By eliminating of the hot filament such problems as thermally "cracking" delicate analyte molecules, outgassing a "hot" filament, high power requirements, filament contamination by outgas species, and spurious em fields are avoid all together. In addition, the ability of produce FEAs using well-known and well developed photolithographic techniques, permits building a QMS having multiple redundancies of the ionization source at very low additional cost.

Felter, Thomas E. (Livermore, CA)

2002-01-01T23:59:59.000Z

428

Portable Source Identification Device  

SciTech Connect (OSTI)

U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation’s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. As the deployment of radiation detection systems proceeds, there is a need to adapt the baseline radiation portal monitor (RPM) system technology to operations at these diverse ports of entry. When screening produces an alarm in the primary inspection RPM, the alarming vehicle is removed from the flow of commerce and the alarm is typically confirmed in a secondary inspection RPM. The portable source identification device (PSID) is a radiation sensor panel (RSP), based on thallium-doped sodium iodide (NaI(Tl)) scintillation detector and gamma spectroscopic analysis hardware and software, mounted on a scissor lift on a small truck. The lift supports a box containing a commercial off-the-shelf (COTS) sodium iodide detector that provides real-time isotopic identification, including neutron detectors to interdict Weapons of Mass Destruction (WMD) and radiation dispersion devices (RDD). The scissor lift will lower the detectors to within a foot off the ground and raise them to approximately 24 feet in the air, allowing a wide vertical scanning range.

Andersen, Eric S.; Samuel, Todd J.; Gervais, Kevin L.

2005-08-01T23:59:59.000Z

429

Empirical Determination of the Energy Loss Rate of Accelerated Electrons in a Well-Observed Solar Flare  

E-Print Network [OSTI]

Empirical Determination of the Energy Loss Rate of Accelerated Electrons in a Well-Observed Solar & Michele Piana1,3 ABSTRACT We present electron images of an extended solar flare source, deduced from the impulsive phase of a solar flare typically appears in the form of accelerated electrons. In the generally

Piana, Michele

430

Constricted glow discharge plasma source  

DOE Patents [OSTI]

A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

2000-01-01T23:59:59.000Z

431

Vehicle Electronics Exponential growth in automotive electronics as  

E-Print Network [OSTI]

1 Vehicle Electronics #12; Exponential growth in automotive electronics as measured by: 2 ­ Number from now: Factor of 10,000 Vehicle Electronics ­ Strategic Drivers #12;Vehicle Electronics ­ Strategic probability of causing a fatal accident translates to thousands of fatal accidents in a popular vehicle model

Duchowski, Andrew T.

432

Roadmap: Electronic Media Electronic Media Sports Production Bachelor of Science  

E-Print Network [OSTI]

Roadmap: Electronic Media ­ Electronic Media Sports Production ­ Bachelor of Science [CI­2013 Page 1 of 4 | Last Updated: 23-May-12/LNHD This roadmap is a recommended semester-by-semester plan requirement #12;Roadmap: Electronic Media ­ Electronic Media Sports Production ­ Bachelor of Science [CI

Sheridan, Scott

433

An electronic radiation of blackbody: Cosmic electron background  

E-Print Network [OSTI]

The Universe owns the electronic radiation of blackbody at temperature 2.725 K, which we call the cosmic electron background. We calculate its radiation spectrum. The energy distribution of number density of electrons in the cosmic electron background becomes zero as energy goes to both zero and infinity. It has one maximum peak near the energy level of 10**(-23) J.

Jian-Miin Liu

2008-02-23T23:59:59.000Z

434

Electronic Survey Methodology Page 1 Electronic Survey Methodology  

E-Print Network [OSTI]

Electronic Survey Methodology Page 1 Electronic Survey Methodology: A Case Study in Reaching Hard, Maryland preece@umbc.edu 2002 © Andrews, Nonnecke and Preece #12;Electronic Survey Methodology Page 2 Conducting Research on the Internet: Electronic survey Design, Development and Implementation Guidelines

Nonnecke, Blair

435

Electrode design and performance of the ORNL positive ion sources  

SciTech Connect (OSTI)

The neutral beam development group at ORNL has designed, constructed, and shipped four 50-kV, 100-A sources to PPL to be used for neutral beam heating of the confined plasma on the PDX tokamak. These sources have higher current capability than scaled-down sources, and they are required to run for 0.5 s as opposed to the 0.3-s requirement for PLT and ISX-B sources. Due to an innovative electrode design, these higher power sources met these requirements and achieved a higher transmission efficiency - 76% of the total input power on target vs 60% for the original ISX-B and modified PLT sources or 40% for the original PLT sources. Using the same electrode design with a tetrode accelerating structure and a new, indirectly heated cathode, repeatable long pulse, high energy conditions of 70 kV, 7 A, 8 s, and 90 kV, 9 A, 5 s were achieved. Grid deformation calculations and Monte Carlo beam line gas deposition algorithms will be discussed. A direct-magnetic-electron-blocking, direct-recovery device is described, and theoretical considerations of it are discussed.

Whealton, J.H.; Gardner, W.L.; Haselton, H.H.

1981-08-01T23:59:59.000Z

436

Low energy spread ion source with a coaxial magnetic filter  

DOE Patents [OSTI]

Multicusp ion sources are capable of producing ions with low axial energy spread which are necessary in applications such as ion projection lithography (IPL) and radioactive ion beam production. The addition of a radially extending magnetic filter consisting of a pair of permanent magnets to the multicusp source reduces the energy spread considerably due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. A coaxial multicusp ion source designed to further reduce the energy spread utilizes a cylindrical magnetic filter to achieve a more uniform axial plasma potential distribution. The coaxial magnetic filter divides the source chamber into an outer annular discharge region in which the plasma is produced and a coaxial inner ion extraction region into which the ions radially diffuse but from which ionizing electrons are excluded. The energy spread in the coaxial source has been measured to be 0.6 eV. Unlike other ion sources, the coaxial source has the capability of adjusting the radial plasma potential distribution and therefore the transverse ion temperature (or beam emittance).

Leung, Ka-Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA)

2000-01-01T23:59:59.000Z

437

Separated spin-up and spin-down quantum hydrodynamics of degenerated electrons: spin-electron acoustic wave appearance  

E-Print Network [OSTI]

Quantum hydrodynamic (QHD) model of charged spin-1/2 particles contains physical quantities defined for all particles of a species including particles with spin-up and with spin-down. Different population of states with different spin direction is included in the spin density (magnetization). In this paper we derive a QHD model, which separately describes spin-up electrons and spin-down electrons. Hence we consider electrons with different projection of spin on the preferable direction as two different species of particles. We show that numbers of particles with different spin direction do not conserve. Hence the continuity equations contain sources of particles. These sources are caused by the interactions of spins with magnetic field. Terms of similar nature arise in the Euler equation. We have that z-projection of the spin density is no longer an independent variable. It is proportional to difference between concentrations of electrons with spin-up and electrons with spin-down. In terms of new model we consider propagation of waves in magnetized plasmas of degenerate electrons and motionless ions. We show that new form of QHD equations gives all solutions obtained from traditional form of QHD equations with no distinguish of spin-up and spin-down states. But it also reveals a sound-like solution we call the spin-electron acoustic wave. Coincidence of most solutions is expected since we started derivation with the same basic equation.

Pavel A. Andreev

2014-05-04T23:59:59.000Z

438

Electronic Spectroscopy & Dynamics  

SciTech Connect (OSTI)

The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

Mark Maroncelli, Nancy Ryan Gray

2010-06-08T23:59:59.000Z

439

National Synchrotron Light Source annual report 1991  

SciTech Connect (OSTI)

This report discusses the following research conducted at NSLS: atomic and molecular science; energy dispersive diffraction; lithography, microscopy and tomography; nuclear physics; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; workshop on surface structure; workshop on electronic and chemical phenomena at surfaces; workshop on imaging; UV FEL machine reviews; VUV machine operations; VUV beamline operations; VUV storage ring parameters; x-ray machine operations; x-ray beamline operations; x-ray storage ring parameters; superconducting x-ray lithography source; SXLS storage ring parameters; the accelerator test facility; proposed UV-FEL user facility at the NSLS; global orbit feedback systems; and NSLS computer system.

Hulbert, S.L.; Lazarz, N.M. (eds.)

1992-04-01T23:59:59.000Z

440

Fingerprints of Disorder Source in Graphene  

E-Print Network [OSTI]

We present a systematic study of the electronic, transport and optical properties of disordered graphene including the next-nearest-neighbor hopping. We show that this hopping has a non-negligible effect on resonant scattering but is of minor importance for long-range disorder such as charged impurities, random potentials or hoppings induced by strain fluctuations. Different types of disorder can be recognized by their fingerprints appearing in the dc conductivity, carrier mobility, optical spectroscopy and Landau level spectrum. By matching our calculations to the experimental observations, we conclude that the long-range disorder potential induced by strain is the most important source of disorder in high-quality graphene on a substrate.

Zhao, Pei-liang; Katsnelson, M I; De Raedt, H

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Linac Coherent Light Source Overview  

ScienceCinema (OSTI)

Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

None

2013-05-29T23:59:59.000Z

442

Linac Coherent Light Source Overview  

Broader source: Energy.gov [DOE]

Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

443

Electron-electron interactions in fast neutral-neutral collisions  

SciTech Connect (OSTI)

Differential electron emission is studied for 50--500 keV H[sup +] and H atom impact on helium. Using the first Born formulation, it is shown that projectile electron-target electron interactions are expected to dominate the differential cross sections for low energy target electron emission induced by fast neutral projectile impact on any target. Measurements of the 15[degrees] electron emission were made in order to investigate this prediction. For low impact energies, a constant ratio between the hydrogen atom and proton impact cross sections was found for emitted electron velocities less than half the projectile velocity, V[sub p] But as the collision energy increased, for electron velocities less than 0.25 V[sub p], the cross section ratio increased as the emitted electron velocity decreased. This is interpreted as a signature of projectile electron-target electron interactions becoming dominant for distant collisions between neutral particles.

DuBois, R.D. (Pacific Northwest Lab., Richland, WA (United States)); Manson, S.T. (Georgia State Univ., Atlanta, GA (United States). Dept. of Physics and Astronomy)

1992-11-01T23:59:59.000Z

444

Electron-electron interactions in fast neutral-neutral collisions  

SciTech Connect (OSTI)

Differential electron emission is studied for 50--500 keV H{sup +} and H atom impact on helium. Using the first Born formulation, it is shown that projectile electron-target electron interactions are expected to dominate the differential cross sections for low energy target electron emission induced by fast neutral projectile impact on any target. Measurements of the 15{degrees} electron emission were made in order to investigate this prediction. For low impact energies, a constant ratio between the hydrogen atom and proton impact cross sections was found for emitted electron velocities less than half the projectile velocity, V{sub p} But as the collision energy increased, for electron velocities less than 0.25 V{sub p}, the cross section ratio increased as the emitted electron velocity decreased. This is interpreted as a signature of projectile electron-target electron interactions becoming dominant for distant collisions between neutral particles.

DuBois, R.D. [Pacific Northwest Lab., Richland, WA (United States); Manson, S.T. [Georgia State Univ., Atlanta, GA (United States). Dept. of Physics and Astronomy

1992-11-01T23:59:59.000Z

445

Alternative Energy Sources – Myths and Realities  

E-Print Network [OSTI]

Alternative Energy Sources - Myths and Realities Walterneed to think about alternative energy sources; the worlddepletion of oil? Alternative energy sources can be divided

Youngquist, Walter

1998-01-01T23:59:59.000Z

446

Quantitative characterization of transboundary flows of used electronics : a case study of the United States  

E-Print Network [OSTI]

Despite growing interest and concern surrounding transboundary movements of used electronics around the world, there is a dearth of data on their movements. Although a multitude of different data sources exist, coherent ...

Miller, Travis Reed

2012-01-01T23:59:59.000Z

447

Nanoscale Triboelectric-Effect-Enabled Energy Conversion for Sustainably Powering Portable Electronics  

E-Print Network [OSTI]

Nanoscale Triboelectric-Effect-Enabled Energy Conversion for Sustainably Powering Portable: Harvesting energy from our living environment is an effective approach for sustainable, maintenance-free, and green power source for wireless, portable, or implanted electronics. Mechanical energy scavenging based

Wang, Zhong L.

448

E-Print Network 3.0 - autotestcon proceedings electronic Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

8-11 September 2008 978-1-4244-2226-50825.00 2008... Hanwei Electronics Co., and FiS, Inc., respectively. These sensors are small and light, but require Source: Chen,...

449

Potential use of electronic information for natural resource management by private landowners in Texas  

E-Print Network [OSTI]

A mail survey of Texas' private landowners was conducted in the fall of 1996 to assess the potential use of electronic information sources as a tool for natural resource management. Eight hundred private landowners in rural communities were asked...

Hays, Amy E

2012-06-07T23:59:59.000Z

450

Overview of Recent Progres on High Repetition Rate, High Brightness Electron Guns  

E-Print Network [OSTI]

Ceramic DC Electron Gun for the Jefferson Laboratory FEL.ALICE (ERLP) DC Photoinjector Gun Commissioning, Proc. ofa 500-kV Photo- cathode DC Gun for the ERL Light Sources in

Sannibale, F.

2014-01-01T23:59:59.000Z

451

Broadband microwave burst produced by electron beams  

E-Print Network [OSTI]

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\\tau_l \\approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.

A. T. Altyntsev; G. D. Fleishman; G. -L. Huang; V. F. Melnikov

2007-12-16T23:59:59.000Z

452

Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring  

SciTech Connect (OSTI)

Laser plasma accelerators have produced high-quality electron beams with GeV energies from cm-scale devices and are being investigated as hyperspectral fs light sources producing THz to {gamma}-ray radiation and as drivers for future high-energy colliders. These applications require a high degree of stability, beam quality and tunability. Here we report on a technique to inject electrons into the accelerating field of a laser-driven plasma wave and coupling of this injector to a lower-density, separately tunable plasma for further acceleration. The technique relies on a single laser pulse powering a plasma structure with a tailored longitudinal density profile, to produce beams that can be tuned in the range of 100-400 MeV with percent-level stability, using laser pulses of less than 40 TW. The resulting device is a simple stand-alone accelerator or the front end for a multistage higher-energy accelerator.

Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Panasenko, Dmitriy; Shiraishi, Satomi; Sokollik, Thomas; Benedetti, Carlo; Schroeder, Carl; Geddes, Cameron; Tilborg, Jeroen van; Osterhoff, Jens; Esarey, Eric; Toth, Csaba; Leemans, Wim

2011-07-15T23:59:59.000Z

453

The Development of the Linac Coherent Light Source RF Gun  

E-Print Network [OSTI]

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

Dowell, David H; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling

2015-01-01T23:59:59.000Z

454

Electron launching voltage monitor  

DOE Patents [OSTI]

An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors. 5 figs.

Mendel, C.W.; Savage, M.E.

1992-03-17T23:59:59.000Z

455

Electron holography of devices with epitaxial layers  

SciTech Connect (OSTI)

Applicability of electron holography to deep submicron Si devices with epitaxial layers is limited due to lack of the mean inner potential data and effects of the sample tilt. The mean inner potential V{sub 0}?=?12.75?V of the intrinsic epitaxial SiGe was measured by electron holography in devices with Ge content C{sub Ge}?=?18%. Nanobeam electron diffraction analysis performed on the same device structure showed that SiGe is strain-free in [220] direction. Our results showed good correlation with simulations of the mean inner potential of the strain-free SiGe using density function theory. A new method is proposed in this paper to correct electron holography data for the overlap of potentials of Si and the epitaxial layer, which is caused by the sample tilt. The method was applied to the analysis of the dopant diffusion in p-Field-effect Transistor devices with the identical gate length L?=?30?nm, which had alternative SiGe geometry in the source and drain regions and was subjected to different thermal processing. Results have helped to understand electrical data acquired from the same devices in terms of dopant diffusion.

Gribelyuk, M. A., E-mail: Michael.gribelyuk@globalfoundries.com; Ontalus, V.; Baumann, F. H.; Zhu, Z.; Holt, J. R. [IBM Systems and Technology Group, Hopewell Junction, New York 12533 (United States)

2014-11-07T23:59:59.000Z

456

Electronic Impact of Inclusions in Diamond  

SciTech Connect (OSTI)

X-ray topography data are compared with photodiode responsivity maps to identify potential candidates for electron trapping in high purity, single crystal diamond. X-ray topography data reveal the defects that exist in the diamond material, which are dominated by non-electrically active linear dislocations. However, many diamonds also contain defects configurations (groups of threading dislocations originating from a secondary phase region or inclusion) in the bulk of the wafer which map well to regions of photoconductive gain, indicating that these inclusions are a source of electron trapping which affect the performance of diamond X-ray detectors. It was determined that photoconductive gain is only possible with the combination of an injecting contact and charge trapping in the near surface region. Typical photoconductive gain regions are 0.2 mm across; away from these near-surface inclusions the device yields the expected diode responsivity.

Muller, E.M.; Smedley, J.; Raghothamachar, B.; Gaowei, M.; Keister, J.W.; Ben-Zvi, I.; Dudley, M.; Wu, Q.

2010-04-07T23:59:59.000Z

457

Optical aperture synthesis with electronically connected telescopes  

E-Print Network [OSTI]

Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances, and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long...

Dravins, Dainis; Nuñez, Paul D

2015-01-01T23:59:59.000Z

458

Power Transmission From The ITER Model Negative Ion Source  

SciTech Connect (OSTI)

In Cadarache development on negative ion sources is being carried out on the KAMABOKO III ion source on the MANTIS test bed. This is a model of the ion source designed for the neutral beam injectors of ITER. This ion source has been developed in collaboration with JAERI, Japan, who also designed and supplied the ion source. Its target performance is to accelerate a D- beam, with a current density of 200 A/m2 and <1 electron extracted per accelerated D- ion, at a source filling pressure of 0.3 Pa. For ITER a continuous ion beam must be assured for pulse lengths of 1000 s, but beams of up to 3,600 s are also envisaged. The ion source is attached to a 3 grid 30 keV accelerator (also supplied by JAERI) and the accelerated negative ion current is determined from the energy deposited on a calorimeter. During long pulse operation ({<=}1000 s) it was found that the current density of both D- and H- beams, measured at the calorimeter was lower than expected and that a large discrepancy existed between the accelerated currents measured electrically and those transmitted to the calorimeter. The possibility that this discrepancy arose because the accelerated current included electrons (which would not be able to reach the calorimeter) was investigated and subsequently eliminated. Further studies have shown that the fraction of the electrical current reaching the calorimeter varies with the pulse length, which led to the suggestion that one or more of the accelerator grids were distorting due to the incident power during operation, leading to a progressive deterioration in the beam quality.. New extraction and acceleration grids have been designed and installed, which should have a better tolerance to thermal loads than those previously used. This paper describes the measurements of the power transmission and distribution using these grids.

Boilson, D. [Association EURATOM-DCU, PRL/NCPST, Glasnevin, Dublin 13 (Ireland); Esch, H. P. L. de; Grand, C.; Hemsworth, R. S.; Krylov, A. [Association EURATOM-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 St Paul-Lez-Durance (France)

2007-08-10T23:59:59.000Z

459

Admittance Test and Conceptual Study of a CW Positron Source for CEBAF  

SciTech Connect (OSTI)

A conceptual study of a Continuous Wave (CW) positron production is presented in this paper. The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB) operates with a CW electron beam with a well-defined emittance, time structure and energy spread. Positrons created via bremsstrahlung photons in a high-Z target emerge with a large emittance compared to incoming electron beam. An admittance study has been performed at CEBAF to estimate the maximum beam phase space area that can be transported in the LINAC and in the Arcs. A positron source is described utilizing the CEBAF injector electron beam, and directly injecting the positrons into the CEBAF LINAC.

Golge, Serkan [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Hyde, Charles E. [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Universite Blaise Pascal, Clermont-Ferrand (France); Freyberger, Arne [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

2009-09-02T23:59:59.000Z

460

Application note : using open source schematic capture tools with Xyce.  

SciTech Connect (OSTI)

The development of the XyceTM Parallel Electronic Simulator has focused entirely on the creation of a fast, scalable simulation tool, and has not included any schematic capture or data visualization tools. This application note will describe how to use the open source schematic capture tool gschem and its associated netlist creation tool gnetlist to create basic circuit designs for Xyce, and how to access advanced features of Xyce that are not directly supported by either gschem or gnetlist.

Russo, Thomas V.

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "laser-driven electron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Precision electron polarimetry  

SciTech Connect (OSTI)

A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. Mo/ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at 300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100%-polarized electron target for Mo/ller polarimetry.

Chudakov, E. [Jefferson Lab 12000 Jefferson Ave, STE 16, Newport News, VA 23606 (United States)

2013-11-07T23:59:59.000Z

462

A graphene electron lens  

SciTech Connect (OSTI)

An epitaxial layer of graphene was grown on a pre patterned 6H-SiC(0001) crystal. The graphene smoothly covers the hexagonal nano-holes in the substrate without the introduction of small angle grain boundaries or dislocations. This is achieved by an elastic deformation of the graphene by {approx_equal}0.3% in accordance to its large elastic strain limit. This elastic stretching of the graphene leads to a modification of the band structure and to a local lowering of the electron group velocity of the graphene. We propose to use this effect to focus two-dimensional electrons in analogy to simple optical lenses.

Gerhard, L.; Balashov, T.; Wulfhekel, W. [Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe (Germany); Moyen, E.; Ozerov, I.; Sahaf, H.; Masson, L.; Hanbuecken, M. [CINaM-CNRS, Aix-Marseille University, Campus Luminy - Case 913, 18288 Marseille (France); Portail, M. [CRHEA-CNRS, Parc de Sophia - Antipolis, rue B. Gregory, 06560 Valbonne (France)

2012-04-09T23:59:59.000Z

463

Precision electron polarimetry  

SciTech Connect (OSTI)

A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\\%-polarized electron target for M{\\o}ller polarimetry.

Chudakov, Eugene A. [JLAB

2013-11-01T23:59:59.000Z

464

Measurements of ultra-low-energy electron scattering cross sections of atoms and molecules  

SciTech Connect (OSTI)

A new experimental technique for the total cross section measurements of ultra-low energy electron collisions with atoms and molecules utilizing the synchrotron radiation is presented. The technique employs a combination of the penetrating field technique and the threshold photoionization of rare gas atoms using the synchrotron radiation as an electron source in order to produce a high resolution electron beam at very low energy. Absolute total cross sections for electron scattering from He, Ne, Ar, Kr, and Xe in the energy region from extremely low electron energy to 20 eV are presented.

Kitajima, M.; Shigemura, K.; Kurokawa, M. [Department of Chemistry, Tokyo Institute of Technology, 152-8551 Tokyo (Japan); Odagiri, T. [Department of Physics, Sophia University, 102-8554 Tokyo, Japan and Department of Chemistry, Tokyo Institute of Technology, 152-8551 Tokyo (Japan); Kato, H.; Hoshino, M.; Tanaka, H. [Department of Physics, Sophia University, 102-8554 Tokyo (Japan); Ito, K. [Photon Factory, Institute of Materials Structure Science, 305-0801 Tsukuba (Japan)

2014-03-05T23:59:59.000Z

465

Hollow electrode plasma excitation source  

DOE Patents [OSTI]

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures. 5 figs.

Ballou, N.E.

1992-04-14T23:59:59.000Z

466

BSTBacterial Source Tracking Conference Proceedings  

E-Print Network [OSTI]

BSTBacterial Source Tracking Conference Proceedings 2012 Bacterial Source Tracking State Conference Conference Proceedings Prepared by: Lucas Gregory, Texas Water Resources Institute Courtney Smith of the Science Conference Texas Water Resources Institute TR-427 June 2012 #12;#12;Texas Water Resources

467

Polarized electron beams at milliampere average current  

SciTech Connect (OSTI)

This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today’s CEBAF polarized source operating at ? 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

Poelker, M. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

2013-11-07T23:59:59.000Z

468

Diamondoid monolayers as electron emitters  

DOE Patents [OSTI]

Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

Yang, Wanli (El Cerrito, CA); Fabbri, Jason D. (San Francisco, CA); Melosh, Nicholas A. (Menlo Park, CA); Hussain, Zahid (Orinda, CA); Shen, Zhi-Xun (Stanford, CA)

2012-04-10T23:59:59.000Z

469